GUIDE TO PROCURING EQUIPMENT AND DESIGNING BUILDINGS … · 2014-08-11 · ¾ The traditional lightin g system based on incandescent lamps, made up of: Filament lamps (incandescent

GUIDE TO PROCURING

EQUIPMENT AND DESIGNING

BUILDINGS USING ENERGY CRITERIA

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A. GUIDE TO PROCURING EQUIPMENT

A.1 Technical and administrative specifications

A.2 Equipment catalogue

A.2.1 Traffic lights

A.2.2 Street Lighting

A2.2.1 Design criteria

A.2.2.2 Choosing equipment

A.2.2.2.1 Lamps

A.2.2.2.2 Auxiliary components: ballasts

A.2.2.2.3 Luminaires

A.2.2.2.4 Equipment and performance maintenance

A.2.2.2.5 Equipment automation

A.2.3 Building indoor lighting

A.2.3.1 Design criteria

A.2.3.2 Choosing equipment: lamps, luminaires, auxiliaries

A.2.3.4 Lighting regulation and control systems

A.2.3.5 Maintenance

A.2.4 Office automation equipment

A.2.4.1 Recommendations for the acquisition of computer equipment

A.2.5 Boilers and air conditioning equipment

A.2.5.1 Design criteria

A.2.5.2 Choosing equipment

A.2.5.2.1 Heating equipment

A.2.5.2.2 Refrigeration equipment

CONTENTS

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A.2.5.2.3 Ventilation

A.2.6 Official vehicles, refuse collection and public transport

A.2.6.1 Light vehicles

A.2.6.2 Lorries and buses

A.2.6.3 Maintenance

B. BUILDING DESIGN

B.1 Project contract

B.2 Design phases

B.2.1 Building orientation

B.2.2 The thermal envelope

B.2.2.1 Façades

a) Exterior finish

b) Insulating material

Fibreglass

Rockwool

Polystyrenes

Polyurethanes

c) Air flow and water vapor control elements

d) Structural elements

e) Interior lining

B.2.2.2 Other types of façades

Curtain walling

Sandwich panelling

B.2.2.3 Openings

B.2.2.4 Roofing

a) Exterior finish

b) Waterproofing and thermal insulating elements

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c) Structural elements

B.2.2.5 Horizontal divisions

B.2.2.6 Interior partitions

B.2.3 Heating and hot water equipment

B.2.3.1 Central heating systems

B.2.3.2 Energy optimization measures

B.2.3.2.1 Central heating systems control

B.2.3.2.2 Improving boiler performance

B.2.3.3.3 Boiler room ventilation

B.2.3.2.4 Energy sources

B.2.3.3 Hot water for sanitation

B.2.3.3.1 Using water saving equipment

B.2.3.3.2 General recommendations

B.2.4 Refrigeration equipment

B.2.4.1 Classification according to compression

B.2.4.2 Classification according to construction

B.2.4.3 Classification according to performance

B.2.4.4 “Free-cooling” and cold accumulation systems

B.2.4.5 Recovering heat from cooling equipment condensation

B.2.5 Ventilation

B.2.5.1 Recovering heat from ventilation air

B.2.6 Artificial illumination installations

B.2.6.1 Lamps

B.2.6.2 Adjustment and control equipment

B.2.6.3 The importance of colour

B.2.6.4 Choosing lamps

B.2.6.4.1 Compact fluorescent lamps (low consumption)

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B.2.6.4.2 Discharge lamps

B.2.6.4.3 Improvements to fluorescentes lamps

B.2.6.4.4 Exterior lighting

B.3 Viability analysis

B.3.1 Active solar energy systems

B.3.2 Central or urban heating systems

B.3.3 Cogeneration systems

B.4 Project viability report

B.5 Construction phases

C. Buildings Catalogue

C.1. Sports facilities

C.1.1 Building orientation

C.1.2 Thermal envelope

C.1.3 Heating and hot water equipment

C.1.4 Refrigeration equipment

C.1.5 Ventilation

C.1.6 Artificial illumination installations

C.2 School complexes




C.2.4 Refrigeration installations

C.2.5 Ventilation


C.3 Office buildings



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C.3.4 Refrigeration installations

C.3.5 Ventilation


APPENDIX: Types of lamp

Lamps and auxiliary equipment

1. Incandescent lamps

2. Mercury vapour discharge lamps

3. Sodium vapour discharge lamps

4. Induction discharge lamps

5. Light emitting diodes (LED)

Glossary of technical terms

Envelope

Climatization

Lighting

GLOSSARY

BIBLIOGRAPHY

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A. GUIDE TO PROCURING EQUIPMENT Nowadays, more often than not, contracts are undertaken mainly prioritising

aspects such as appearance, price or execution time and very little attention is

paid to the energy efficiency aspects of the property or service which is being

acquired.

The objective of this guide is to act as a tool providing support to those

municipal officials in charge of the acquisition of equipment and of contracting

projects and the construction of new buildings, so that they take into

consideration any energy efficiency repercussions which may come about from

their decisions.

In this first section, we have included advice and minimum technical

specifications to be applied to the purchase of equipment (lighting equipment,

traffic lights, boilers, vehicles, etc), listing the different types of technology

available and the advantages and disadvantages of each of these. Wherever

possible, we have also included any associated investment estimates and the

simple return period of the overinvestment of each option with respect to the

lower investment possibility, taking into account any foreseeable energy saving.

The second part of the guide aims to provide recommendations regarding

solutions for new buildings which aim to reach a maximum exploitation of solar

energy and a maximum energy efficiency of buildings.

A.1. TECHNICAL AND ADMINISTRATIVE SPECIFICATIONS The running of any type of equipment implies the consumption of energy which

will have to be paid for during the whole working life of the device. This is why it

is essential for any public administration to take into account the energy

demand of any equipment they purchase.

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To this respect, when it comes to acquiring equipment, all public administrations

should take into account energy criteria beyond the legally required minimum.

Obviously, not all councils have a qualified technical team to specifically define

any particular energy efficiency requirements which are needed by the

equipment they are going to acquire. Furthermore, even in those organisations

where they do have technical personnel, those solutions which they take into

consideration may not be the only ones available or they may not even be the

most adequate or compatible with the sought after application. For this reason,

we recommend to always include a clause in the specifications for technical

conditions, which indicates that the justified increase of the energy efficiency of

the equipment being acquired will be evaluated as an improvement. As a result,

bidders will be obliged to present highly efficient equipment.

The specifications for administrative conditions should specify the importance of

the energy efficiency evaluation, along with any other aspects which are

considered of interest, such as price, appearance, usefulness, execution time...

We recommend that the percentage corresponding to energy efficiency should

not be lower than 20% of the total maximum number of points.

We believe it is necessary to highlight that the administration should play an

exemplary role in this field, justifying any possible surcharges which may come

about when meeting higher energy efficiency requirements.

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SUMMARY OF SECTION A.1

- Generating and consuming energy gives rise to a strong environmental

impact.

- Purchasing equipment conditions the consumption of energy during the

device’s working life.

- Public administrations are under an obligation to provide an example of

the rational use of energy.

- The specifications for the purchase of equipment by any public

administration should demand the maximum energy efficiency

classification. Besides, an objective points system should be included in

order to prioritise those justified improvements in energy efficiency

offered by bidders.

- Acting as an energy efficient role model justifies any slight surcharges

paid out by the administration.

A.2. EQUIPMENT CATALOGUE A.2.1. Traffic Lights There are two types of technology available for vertical signposting in cities:

The traditional lighting system based on incandescent lamps, made up

of:

Filament lamps (incandescent or halogen).

Parabolic reflector.

Glass or coloured metalacrylate diffuser.

Lighting system based on LED optics made up of:

Printed circuit with welded LEDs and electronics located inside an

enclosing protection system.

Transparent metalacrylate cover.

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The main characteristics of traffic lights with incandescent and halogen lamps

are the following:

High consumption. The power of each of the lamps ranges from 25 to

100 watts, the most common being 70 W.

Low reliability. The lifetime of the lamps used for traffic lights is shorter

than 8,000 hours (this varies from 2,000 up to 8,000 hours depending

on the type of lamp.)

Low operational security. When the lamp fails, the corresponding

signage is left without illumination.

High maintenance. It is necessary to change the lamps at least one a

year (every three months for those with a shorter lifetime), to clean the

inside once a year (reflector and lens) and outside (lens).

Existence of the “ghost effect” caused by sunlight. When the lamps are

off and sunlight falls on the reflectors, it seems that they are on.

Low contrast with sunlight. Low vision at longer distances.

Non-uniform illuminated signposting.

Sensitive to vibrations and to vandalism. Any vibration caused by the

wind and by traffic usually results in the failure of the lamps.

Furthermore, the equipment is highly vulnerable to vandalism

(breakages).

The main characteristics of LED traffic lights with respect to those using

incandescent lamps, are the following:

Much lower consumption. Traffic lights with LEDs have a consumption

ranging between 5 and 15% of incandescent or halogen lamps: this

means an energy saving of 85 to 95%.

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Higher reliability. The lifetime of lamps being used in traffic lights today

is shorter than 8,000 hours, in contrast to the 100,000 hours of lifetime

of LEDs (the number of failures after 100,000 hours of operation is

lower than 3%).

Higher operating security. The failure of a LED represents a very small

total loss of illumination (less than 5%)

Minimum maintenance. A reduction in the cost of maintenance due to

the longer working life of the optic device and to the absence of a

reflector. The exterior of the lens needs to be cleaned only once a year.

The LED card can be changed after more than 10 years.

Simple substitution. The optical units can directly substitute those using

incandescent lamps.

Elimination of the “ghost effect” caused by sunlight. The LED traffic

lights do not need any type of reflecting element inside the device in

order to emit light (the reflecting element causes the “ghost effect” in

traditional traffic lights when they are in direct sunlight).

Neutral condition when turned off. Colourless lens, thus avoiding any

confusion.

Optic unit proof against sunlight. Ultraviolet rays do not affect the

colouring of the optic discs.

High contrast with sunlight. Better vision at longer distances.

Uniform illuminated signposting.

Greater road safety. LED traffic lights provide greater brilliance and

brightness. Greater resistance to vibrations caused by the wind and by

traffic.

Greater impact resistance. Reduction of the effects of vandalism.

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Pedestrian traffic light including a ‘time

remaining’ countdown Vehicle traffic light

Below we have detailed the investments corresponding to traffic lights featuring

LED technology and the recovery of additional investments with respect to

traffic lights with incandescent lamps. Traffic lights featuring LED technology

require greater investments than those traffic lights with incandescent lamps (or

halogen lamps) but as a result of their lower energy consumption, their low

maintenance and their long working life, the required additional investment

could be recovered in about 5 years.

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DOSSIER FOR TRAFFIC LIGHTS WITH LED OPTICS

Advantages:

Low consumption: 4 – 15 W/optic.

Greater reliability: lifetime of 100,000 hours (about 20 years of normal functioning).

Low maintenance: very long lifetime and absence of a reflector (the outside needs to be cleaned only once a year)

Elimination of the “ghost effect” caused by sunlight: traffic lights without reflectors and with colourless lenses.

High contrast and uniform signposting.

Improved road safety: increased brilliance, brightness and resistance to vibrations caused by the wind and by traffic.

Disadvantages:

High price.

Additional costs:

Below is an estimate of the costs and return period on the additional investment with respect to a traffic light with incandescent or halogen lamps (including installation and VAT): (Vehicle traffic light operating 48.33% on red, 3.33% on amber and 48.33% on green. Pedestrian traffic light operating 50% on green – red).

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Equipment Additional investment Return

Green LED disc 200 mm 210 euros 7 years

Amber LED disc 200 mm 80 euros > 10 years

Red LED disc 200 mm 80 euros 3 years

Green LED disc 100 mm 80 euros 3 years

Amber LED disc 100 mm 70 euros > 10 years

Red LED disc 100 mm 70 euros 3 years

Green LED pedestrian disc 160 euros 8 years

Red LED pedestrian disc 140 euros 7 years

Technical specifications recommended for LED traffic lights:

- Size (diameter): 100, 200 or 300 mm. - Compliances and approvals: EN12368. - Luminous intensity: class A2/1. - Distribution of luminous intensity: class W. - Luminous uniformity (min : max.): 1:10. - Ghost effect maximum: class 1. - Supply voltage: from 24 to 250 V – 50 Hz, or 12 V DC. - Voltage tolerance boundary (minimum): ± 10%. - Stabilized casing protected against UV radiation. - Protection against peaks and transitions in the supply voltage. - Protection against overintensity. - Operating temperature: Class A s/ EN12368 (-40ºC to 60ºC). Trial s/

EN600068-2. - Relative operating humidity: 95%. Trial s/ EN60068-2. - Resistance to vibration: Trial s/ EN60068-2. - Degree of protection: IP66 s/ IEC60529. - Voltage factor above 0.9.

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- Consumption of vehicle traffic light: 200 mm: ≤ 10 W 300 mm: ≤ 20 W

- Consumption of pedestrian traffic light: ≤ 6 W - Dominant wavelength:

Red ≥ 618nm., Amber: 586 to 596nm, Green: 490 to 510nm. - Number of LEDs:

200 mm – 300 mm disc: green, amber and red ≥ 100 units. Pedestrian disc: ≥ 30 units.

- Loss of brilliance due to the failure of an LED: ≤ 4% - Guarantee: ≥ 5 years.

SUMMARY OF SECTION A.2.1

Energy efficient technology based on the use of LED optics should be used for

traffic lights

A.2.2. Public lighting Most of the electric energy which is consumed in the majority of councils

corresponds to public lighting, and this means a substantial expense in this field

(up to 70% of the total energy expenditure); therefore an adequate design and

good management of this equipment is necessary.

Different studies have been carried out and they confirm that the level of safety

on public roads can be increased considerably by an adequate design of

lighting systems. According to information provided by the International

Commission on Illumination (CIE), the correct illumination of public

thoroughfares for vehicular traffic reduces the total number of accidents by 30%

at night.

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In this chapter, we have included advice regarding energy optimization and

equipment characteristics which should be considered, not only when lighting

equipment is renewed but also when new installations are being provided. This

advice takes into account the compliances and approvals which establish the

minimum and maximum illumination levels and it aims to compatibilize an

optimum quality public lighting service with a rational use of energy. In order to

do this, an adequate approach must be carried out from two points of view:

Design phase: when it comes to starting a public illumination project, it is

necessary to adapt the design to the final use, introducing the most

adequate technology. With regard to the type of equipment that can

meet the corresponding needs, that which is the least expensive should

be chosen (including any expenditure derived from the running of the

devices throughout their working life).

Management and maintenance: the correct running of any public lighting

facility, and as a result an increased energy efficiency of the same, can

be achieved by means of good management and maintenance, which

generally consists of carrying out a constant follow-up of the luminance

and security parameters.

A.2.2.1. Design criteria

Below we have detailed the parameters which should be taken into account

when carrying out public illumination projects following the requirements for

greater efficiency and energy saving, without ignoring the minimum illumination

levels called for by regulations in each case.

These recommendations are based on compliances laid out by the International

Commission on Illumination (CIE), the Commission for European Normalization

(CEN) and the International Electrotechnic Commission (CEI), as well as

European EN standards.

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Design criteria according to the type of thoroughfare.

The main objective of any public lighting is to provide perception reliability,

maximum security and visual comfort.

The parameters which influence perception reliability are the following:

Average illuminance of the road surface: Lm

Global uniformity, U0: Lmin/Lm

(minimum illuminance / average illuminance)

Distracting glare

And the parameters which influence visual comfort are:

Longitude uniformity, U1: Lmin/Lmax

(minimum illuminance / maximum illuminance)

Unpleasant glare: G

Visual guide

(The attached glossary includes a definition of all of this terminology).

These parameters should be taken into account in order to achieve an optimum

installation of public lighting. Beforehand, the different areas to be lit should be

established and differentiated, following the criteria laid down by the

International Commission on Illumination (CIE) to establish quality standards for

public lighting.

As a reference, below we have included a table indicating the classification of

public thoroughfares:

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Thoroughfare class Type of traffic density Type of thoroughfare Examples

Mot

or v

ehic

les

A

Heavy, high speed motorized traffic

Thoroughfares with separate lanes, without level crossings and with totally controlled access

Motorways

Freeways

B

Important thoroughfares for motorized traffic including separate lanes for slow vehicles and/or pedestrians

‘A’ roads

Main roads and ring roads

Radial roads C

Heavy, moderate speed motorized traffic1 or heavy, moderate speed and high speed mixed traffic

Important multi-purpose public thoroughfares, rural or urban

Mix

ed v

ehic

les

D Slow mixed traffic most of which is slow or pedestrian traffic

Public thoroughfares in cities or shopping centres. All lanes carry heavy and slow mixed traffic or a high number of pedestrians

Roads

Shopping streets

Industrial roads, etc.

E Mixed traffic of limited speed and moderately heavy

Thoroughfares connecting residential areas to the main road network (types A to D)

Connecting roads

Local streets, etc.

Depending on the type of public thoroughfare, the procedure applied in order to

carry out an illumination project is different. The following table provides a brief

summary of the standards and minimum illumination quality levels which are

established for each type of thoroughfare:

1 Speed limit 70 km/h.

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Thor

ough

fare

cl

ass Nearby

areas

Luminance level (*) Uniformity Glare limit

Average luminance

(cd/m2)

Global uniformity

U0

Longitude uniformity U1

Glare control index (G)

Threshold increase

(%)

A Any 2

0.4

0.7 6 10 (**)

B Light 2

0.7 5 10

Dark 1 6 10 (**)

C Light 2

0.5 5 20 (**)

Dark 1 6 10

D Light 2 0.5 4 20

E Light 1

0.5 4 20

Dark 0.5 5 20 (**) (*) The recommended luminance is the average luminance depending on the type of thoroughfare. With the aim of maintaining the aforementioned level, a depreciation factor no greater than 0.8 must be taken into consideration, depending on the type of luminaire and the air pollution level. For more details, see CIE publication number 33. “Depreciation of Installations and Their Maintenance in Road Lighting”. (**) In light of the scarce experience in the application of the concept “Threshold increase” it would be better not to reach values greater than 0.7 times the value shown in the table.

In general, the following illumination levels can be used as a reference for the

different types of thoroughfares which are indicated:

Average level of illumination (lux)

Areas for pedestrian 8-15

Areas for pedestrian and slow speed vehicles 10-25

Areas for moderate speed vehicles 15-30

A.2.2.2. Choosing equipment A.2.2.2.1. Lamps.

In order to reduce expenditure (installation, running and maintenance), the

choice of lamps should take into account the following:

Luminous efficacy (lum / W): the most luminously efficient lamps

should be used (100 lum / W or above). The greater the luminous

efficacy, the fewer the number of lamps, luminaires and fixtures

which therefore means a smaller initial investment and lower running

costs.

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Working life / Lifetime: the longer the working life, the lower the

maintenance costs. It would be convenient to install lamps with a

working life of over 12,000 hours.

Lighting quality: the higher the colour rendering index, the greater the

capacity to reproduce the “real” colours of objects. The index chosen

for public lighting should be whatever is strictly necessary for the area

to be lit.

Below we have included a table comparing the different types of lamps used in

exterior lighting, which also indicates their recommended areas of use. The

attached appendix includes more information about these.

Main characteristics of exterior lighting lamps

* CRI: colour rendering index. ** Due to the low efficiency of this type of lamp, it is only convenient for illumination during short periods (monument illumination - activated by coins; security lighting accompanying discharge lamps - working only during the re-ignition period of the discharge lamps). *** Taking into account the consumption of the system (lamp, antenna, HF generator)

Type of lamp Efficacy (lumen/W)

Working life (hours) CRI (*) Re-ignition Recommended use

Halogen 13 to 25 2,000 – 5,000 100 Immediate Security lighting and monuments (**)

Fluorescent tubes 40 to 100 6,000 – 79,000 60 - 90 Immediate

Tunnels, underpasses,

bridges

Induction 65-80 (***) 60,000 80 - 89 Immediate Urban streets

Mercury vapour 35 to 60 8,000 – 16,000 50 - 60 10 minutes Parks and gardens

Metal halide 70 to 120 10,000 – 16,000 60 - 95 15 minutes

Urban streets, shopping areas,

monuments

High pressure sodium vapour 66 to 150 12,000 –

18,000 20 - 65 1 to 15 minutes

Urban streets, roads and

motorways, large spaces, monuments

Low pressure sodium vapour 100 to 200 12,000 NULL 0.2

minutes

Roads and motorways, tunnels,

underpasses, beaconing

LED 10 to 20 100,000 75 - 80 Immediate Beaconing, signposting

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Technical specifications recommended for lamps:

- CE marking.

- Performance: ≥ 100 lumen/watt

- Working life: ≥ 12,000 hours.

- Colour rendering index: equal to or above that recommended for the type of area to be lit.

- Maximum pressure arc tolerance: ± 10 volts.

A.2.2.2.2. Auxiliary equipment: ballasts

Discharge lamps require some type of stabilising element for their electric circuit

(ballasts) and moreover, in some cases it is necessary to include an ignition

component (starter) and an element to correct the power factor (condenser).

With all ballasts there is a loss of energy (electromagnetic or electronic)

depending on the type of ballast and also on the type and power of the lamps.

In the table below we can see the percentage of power loss for this equipment,

in relation to the power of the lamp, depending on these factors:

Type of lamp Type of ballast

Standard electromagnetic

Low-loss electromagnetic Electronic

Fluorescent 20-25% 14-16 % 8-11 %

Discharge 14-20% 8-12 % 6-8 %

Low voltage halogen 15-20% 10-12 % 5-7 %

As we can see in the table above, electronic ballasts are less subject to losses

than those of the electromagnetic type. Furthermore, electronic ballasts stabilize

and regulate the pressure therefore helping to prolong the lifetime of the lamps

and to maintain their characteristics for a long time, and they also assure an

automatic power supply cut whenever the lamp is faulty.

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In equipment with electromagnetic ballasts, a 1% oversupply of voltage can

mean a 3% increase in consumption and if the equipment is running constantly

with a voltage undersupply of 7%, this could mean a 50% increase in the

mortality of the lamps and equipment. This can be avoided by using electronic

ballasts.

The price difference between both types of devices (the electronic variety are

more expensive) can be paid off in about six years of their working life.

DOSSIER FOR ELECTRONIC BALLASTS

Advantages:

A reduction in consumption of more than 25% with respect to the low-loss electromagnetic variety.

An increase in the efficiency of the lamp (fewer lamps have to be installed in order to obtain the same illumination level).

An increase in the lifetime of the lamp of up to 50%. A reduction in maintenance costs.

No starting device is needed to ignite the lamp, which means a further reduction in maintenance costs.

No condenser is needed to correct the power factor, given that the reactive energy demand of electronic ballasts is negligible.

A reduction in noise output.

A constant illumination level, not affected by variations in pressure.

Automatic disconnection whenever lamps are faulty or burnt-out.

They include protection against voltage oversupply.

It is possible to regulate the level of illumination.

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Disadvantages:

Higher price than electromagnetic ballasts.

Additional costs:

Below we have included additional costs and the return period for the additional investment with respect to a low-loss electromagnetic ballast (including installation and VAT): (average values for 4,300 hours of operation per year).


Electronic ballast for metal halogen lamps

100 euros 6 years

Electronic ballast for high pressure sodium vapour lamps

Electronic ballast for low pressure sodium vapour lamps

Electronic ballast for colour-corrected mercury vapour lamps

Recommended technical specifications for ballasts:

- Compliances and approvals:

- RFI: (conducted) EN 55015

(radiated) EN 55022

- Immunity EN 61547

- Humidity EN 60068-2-3-Ca

- Safety EN 60928 (electromagnetic ballasts EN 60922)

- Harmonics EN 61000-3-2

- Performance: EN 60929 (electromagnetic ballasts EN 60923)

- CE marking.

- Powerloss (W) < 10% Nominal Lamp power

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- Rated mains Voltage (V): 220 - 240

- With tolerances for performance (V): 202 - 230 - 254

- With tolerances for operation (V): 198 - 230 - 264

- Mains frequency (Hz): 50/60

- Power factor (nominal power) > 0.95

- Earth leakage current per ballast (mA) < 0.5

- End of lamp life protected.

- Ambient temperature range (°C): -40…50

- Failure rate at nominal case temperature (%/1000h): 0.35

- Lifetime at nominal case temp.(Max. 5% failures) hours: 60,000

There are also ballasts, both electronic and electromagnetic, which allow for a

reduction of power and of the luminous flux emitted by the lamp (double level

ballasts), and these are dealt with in section “A.2.2.2.5. Equipment automation”.

On the other hand, induction lamps require a high frequency generator adapted

to the type of lamp, which should be purchased along with the lamp.

A.2.2.2.3. Luminaires Luminaires can be defined as any type of equipment which distributes, filters or

transforms light from one or from several lamps, comprising all the necessary

components for fixing and protecting the lamps. In short, the luminaire is the

fixture which distributes the light supplied by the lamp.

From an energy point of view, there are three main criteria to be taken into

account when choosing a luminaire:

Luminaire performance: ŋ = Luminaire flux / Lamp flux (%)

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The performance of the luminaire should consider the bottom half and

not the top of the fixture. In order to avoid light pollution, any upward light

emissions should be reduced as far as possible (it is advisable to choose

luminaires with an upward flux performance of zero or close to zero) and

to maximize the tapping of light emitted by the lamp, luminaires should

be chosen with a high downward flux performance. Choosing high-

performance luminaires leads to a reduction in power supply and also in

the number of lamps that are used, which therefore means saving

energy.

Maintenance and depreciation factor: The reduction of luminance over

time is mainly caused by the reduction of the flux emitted by the lamps

due to their aging and due to factors such as dirt on the lamp and on the

luminaire, humidity, etc. The use of luminaires with a high level of

protection against dust and water enables the illumination levels to be

maintained over time and reduces maintenance costs.

Glare: In order to reduce the effects of glare and to install efficient

lighting facilities, we recommend the power supply for the sources of light

to be limited depending on the mounting height, as detailed in the

following table:

Mounting height (m)

Recommended luminous flux (lm)

Type of lamp

h.p.s.v. (W) m.h.

(W) m.v. (W)

l.p.s.v. (W)

5 5,000 50 - 70 70 50 - 80 -125 18 - 35

8 7,500 - 17,000 100 - 150 100 – 150 250 55 - 90

10 17,000 - 32,000 150 - 250 150 – 250 400 135

12 32,000 - 56,000 250 - 400 250 – 400 700 180

15 56,000 - 90,000 400 - 600 400 – 600 1,000 ---

20 90,000 - 130,000 600 - 1,000 600 - 1,000 --- --- h.p.s.v.: High pressure sodium vapour. l.p.s.v.: Low pressure sodium vapour. m.v.: Mercury vapour. m.h.: Metal halogen.

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When choosing the height of the mountings, (poles, posts), first of all energy

and environmental criteria should be taken into account, before any type of

esthetic criteria.

Recommended technical specifications for luminaires:

- CE marking.

- Compliances and approvals: EN 60598

- Luminaire: IP 66 (EN 60598), ≥ IK 08 (EN 50102).

(Not only the luminaire, but also the optics, in order to be able to use electronic ballast).

- Light injected alloy body and mounting base.

- Anodized aluminium reflector.

- Screws: AISI 316

- Mounting system: hot-dipped galvanized steel.

- Upward flux performance:

Luminaires featuring asymmetric distribution ≤ 0.7%

Luminaires featuring symmetric distribution (globe or

mushroom style) ≤ 2.5%

- Downward flux performance:

Luminaires featuring asymmetric distribution ≥ 80%

Luminaires featuring symmetric distribution (globe or

mushroom style) ≥ 75%

Luminaires should be chosen in terms of their photometric characteristics and

light pollution control.

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A comparative example of two types of luminaires.

Below we have detailed a comparative example of an installation including

a globe type luminaire, with a protection index IP-55 and featuring a superior

hemisphere flux from the lamp (F.H.S.inst) of 40%, as opposed to another

luminaire with an index of IP-66 and an F.H.S-inst of 0%.

Characteristics of the street:

Length: 10 m

Longitude: 500 m

Pedestrian thoroughfare including vehicular traffic.

Recommended illumination level: 10 – 25 lux

Option 1:

Globe type luminaire. IP 55 FHSinst 40%

Height: 3 m

Distance between luminaires: 15 m

Installation: parallel, interpolated

Lamp: VSAP 100 W

Luminous flux of the lamp: 9,600 lm.

Option 2:

Luminaire: with IP 66 and an FHSinst of 0%.

Height: 7 m

Distance between luminaires: 30 m

Installation: parallel, interpolated

Lamp: VSAP 100 W

Luminous flux of the lamp: 9,600 lm

22

Results of option 1:

Average operational level: 9.15 lux

Average uniformity: 0.28

Extreme uniformity: 0.08

Degree of glare: 2

Number of necessary light sources: 33

The energy consumption, in this case, is of 11,253 kWh (taking into

account the fact that the installation has an intelligent ignition system and

a double level system).

Results of option 2:

Average operational level: 11.85 lux

Average uniformity: 0.46

Extreme uniformity: 0.21

Degree of glare: 7

Number of necessary light sources: 17

For this case, the energy consumption is reduced to 5,797 kWh (taking

into account the fact that the installation has an intelligent ignition system

and a double level system).

CONCLUSIONS:

The use of a more efficient luminaire will bring about:

- An improvement in the levels of illumination using the same

lamp and fewer sources of light (a 23% increase).

- An energy saving and, as a result, economic saving (about

5,456 kWh/year and about 475 €/year) .

- A reduction of light pollution in the area.

- A reduction of the degree of glare of up to 5 points.

23

If the lighting installation were new, the investment for both options would be:

Investment option 1 (€) 45,000

Investment option 2 (€) 35,000

The price difference for the investment implies a reduction of 10,000€ for

option 2, given that:

- Even though the luminaires in option 2 are more expensive, as

there are fewer sources of light, this would imply a reduction in

the final investment to be made.

- The reduced quantity of sources of light to be installed would

mean a lower installed power which would allow for the use of

smaller section conductors and consequently a reduction in

costs.

- The lower installed power in option 2 would allow double level

equipment to be used at the start of the series, using less power

and also costing less.

- Furthermore, the use of fewer light sources at a greater height,

would imply a reduction in base and support costs (columns)

and their corresponding earth terminals.

A.2.2.2.4. Equipment and performance maintenance It is necessary to carry out a periodic maintenance of the equipment in order to

maintain the energy efficiency of these: cleaning the luminaires, changing lamps

and condensers, checking the supports.

Any maintenance contracts should include the average illumination level to be

maintained and also the regularity with which any maintenance actions are to

be carried out in order to maintain the required illumination level.

24

A.2.2.2.5. Equipment automation Ignition systems.

There are two main types of ignition for public lighting equipment:

- Dusk to dawn switches

- Astronomic clock switches

Dusk to dawn switches control the ignition and shut-down of the equipment in

terms of the natural illumination level, but its main disadvantage is the loss of

sensitivity due to dirt. When these become dirty, the equipment operates for

longer periods of time than they should, which implies an unnecessary energy

consumption.

An astronomic clock switch is a device which is designed to switch street

lighting on and off, coinciding exactly with sunrise and sunset wherever they

may be located, at any day of the year, by using information regarding the

longitude and latitude position of the location.

With regard to equipment using dusk to dawn switches to turn lighting on and

off, the use of astronomic clock switches reduces the operational time of the

installation by 5%, which means that the return on investment for this equipment

(about 300€) is paid off in less than one year.

Recommended technical specifications for dusk to dawn switches:

- Compliances and approvals: EN 60669-2-1

- Nominal voltage: 230 Vc.a.

- Nominal frequency: 50 Hz

- Overvoltage breakage limit: 10 A / 250 Vc.a.

- Ignition/shut-down delay: 60 seconds.

25

- Actual consumption: ≤ 8 VA

- Operating temperature: from -30 ºC to +50 ºC

- Sensitivity: 5 - 300 lux logarithmic

- Class II protection according to EN 60335

- IP 65 protection according to EN 60529

Costs (including installation and VAT):

Equipment Investment

Dusk to dawn switch 100 euros

Recommended technical specifications for astronomic clock switches:

- Compliances and approvals: EN 60730-2-7

- Adjustment depending on geographic area.

- Step on – off correction ± 99 minutes.

- Astronomic time update every 4 days.

- Programme block by means of password.

- Automatic summer – winter time adjustment.

- Special programmes for weekends and bank holidays.

- Nominal voltage: 230 Vc.a.

- Nominal frequency: 50 Hz

- Overvoltage breakage limit: 10 A / 250 Vc.a.

- Operational reserve: ≥ 4 years without power supply at 23 ºC

- Operational accuracy: ± 1 s/day between 20 ºC and 30 ºC

- Actual consumption: ≤ 6 VA

- Operating temperature -20 ºC to +45 ºC

- Class II protection according to EN 60335

- IP 52 (minimum) protection according to EN 60529

26

Additional costs

Below we have included the additional costs and return period on the additional investment for a dusk to dawn switch (including installation and VAT): (average values for 4,300 hours of operation per year).


Astronomic clock switch 300 euros 1 year Illumination level regulation system.

The energy consumption of public lighting equipment which uses discharge

lamps can be reduced during early morning hours or when visual requirements

are not as demanding by means of a reduction in the luminous flux. There are

three systems that can be used to put this reduction into practice:

- Double level electromagnetic ballasts.

- Voltage regulators at the start of the series.

- Systems based on electronic ballasts.

Double level electromagnetic ballasts

This type of equipment functions independently with each lamp (it is necessary

to install one device per lamp), reducing the supply voltage to the lamp

whenever it receives a programmed signal, and this means a reduction of

consumption and of the quantity of light which is emitted.

There are different types of devices:

Consumption reduction units with pilot cable.

This equipment needs an additional pilot cable connected to the public

lighting in order to be able to control the lamps. Furthermore, they

usually include a clock and a timer inside the control box where the

double level operating instructions are programmed.

27

The consumption reduction start-up time can be chosen by means of

the clock programming.

Consumption reduction units without pilot cable.

This type of equipment controls the lamps by means of programming

for each device. This programming can be carried out via

microswitches which are included in the device itself or it can be

programmed on assembly.

The disadvantage of this type of equipment resides in how difficult it is

to change the programming at any given moment, due to the fact that

any update would have to be carried out source by source, which

means an increased expense.

The further advantage of double level ballasts is the longer lifetime of the lamps,

given that generally any harmful power surges are produced at times when the

reduced level illumination is connected.

28

DOSSIER FOR DOUBLE LEVEL ELECTROMAGNETIC BALLASTS

Advantages:

A consumption reduction of about 35 to 40% with a reduction in the flux between 45 to 55%.

Diminishing of the effect of power surges on the lamps during nighttime periods of general low demand.

Disadvantages:

Installation is required at each light source, which makes it difficult to install them in existing equipment.

Additional costs:

Below are the costs and the return period for the additional investment with respect to single level electromagnetic ballast (including installation and VAT): (average values for 4,300 hours of operation per year).


Double level electromagnetic ballast with pilot cable

60 euros 4 years

Double level electromagnetic ballast programmed by means of microswitches

45 euros 3 years

29

Recommended technical specifications for double level electromagnetic ballasts:



(radiated) EN 55022

- Immunity EN 61547


- Safety EN 60922


- Performance: EN 60923

- CE marking.

- Powerloss (W) < 10% Nominal Lamp power

- Voltage (V): 230 V.

- Maximum temperature at the ballast windings (Tw): 130ºC

- Lamp power reduction: 35 – 40%.

- Lamp flux reduction: 45 – 55%

- Mains frequency (Hz): 50/60

- Earth leakage current per ballast (mA) < 0.5

- Ambient temperature range (°C): -20…50



30

Flux reducers at the series start

This equipment, installed alongside the control, protection and measurement

panel, acts just like consumption reduction units, the only difference being that

instead of carrying out the voltage modification independently for each lamp,

they control the entire installation as a whole. That is to say, the flux reducer

reduces the supply voltage to the lamp and ballast as one, in order to obtain

power reductions of around 40% for luminous flux reductions of 50%.

This equipment is basically made up of a transformer with multiple sockets, a

clock to establish the reduction period and commutators to choose the voltage

output.

The flux reducer should feature voltage stabilization and independent regulation

for each phase.

The working principle of this equipment is based on an autotransformer which is

supplied directly by the voltage from the mains in its primary circuit. Its terminals

in the secondary circuit are connected to the output via the static switches of the

electronic unit.

Static switches are semiconductors controlled by an electronic system so that at

any given moment there is only one active semiconductor (the one whose

terminal is supplying the desired output voltage at the time).

The electronic control unit is in charge of managing these decisions (by means

of a reference voltage which is recorded in a memory), it constantly monitors

the equipment’s output voltage in order to activate one thyristor or another,

depending on the terminal it should commutate to compensate the output.

Whenever a particular energy saving order is activated, in each of the phases

the microprocessor will slowly diminish this reference voltage in stages, so that

the output will remain stabilized, even during the change itself.

31

DOSSIER FOR STABILIZER-REDUCERS AT SERIES START (static)

Advantages:

Consumption reduced by 40% with a flux reduction of 50%.

Diminishing of the effect of power surges on the lamps (not only at maximum power level but also at a reduced level): there is neither over-consumption nor a reduction of the lamps’ lifetime due to power surges.

Simple installation. In existing installations it is more recommendable than mounting double level ballast.

Disadvantages:

Those light sources which are further away from the reducer are supplied with a lower voltage than closer sources (due to power drops in the lines), which may cause these sources to turn off if the voltage drops too much during the reduction period.

Additional costs:

Below are the costs and the return period for the additional investment with respect to double level electromagnetic ballast (including installation and VAT): (average values for 4,300 hours of operation per year).


10 kVA stabilzer-reducer equipment 2,400 euros 6 years








32

Recommended technical specifications for stabilizer-reducers at series start:

- CE marking.

- Independent control per phase.

- Losses (W) < 3% total power of the lamps.

- Mains input (V): 230/400 (three-phase + neutral)

- With tolerances for performance: ±8%

- Maximum control for output voltage: -20 %

- Mains frequency (Hz): 50 ± 2

- Operating ambient temperature (°C): -40 ... +45

- Humidity (max): 95%

- Noise at 1 m.: < 35 dB(A).

Electronic ballasts.

- Double level electronic ballasts.

These are equivalent to double level electromagnetic ballasts, but they include

electronic technology. There are models which feature pilot cables,

microswitches and with both control options.

They are characterized by the fact that they have fewer losses than their

electromagnetic counterparts, they stabilize the output voltage and they require

neither correction of the power factor nor a starting device.

They should be installed in luminaires with IP66 protection in the area where the

equipment is located.

33

DOSSIER FOR DOUBLE LEVEL ELECTRONIC BALLASTS

Advantages:

A reduction in consumption of more than 50% with respect to the electromagnetic variety.



No condenser is needed to correct the power factor, given that the reactive energy demand of electronic ballasts is negligible.

A reduction in noise output.

A constant illumination level, not affected by variations in pressure.



Disadvantages:


Additional costs:

Below are the costs and the return period for the additional investment with respect to double level electromagnetic ballast (including installation and VAT): (average values for 4,300 hours of operation per year, during half of which the power reduction is applied).


Double level electronic ballast 120 euros 7 years

34

Recommended technical specifications for double level electronic ballasts:



(radiated) EN 55022

- Immunity EN 61547


- Safety EN 60922


- Performance: EN 60923

- CE marking.

- Reduction level: 40% or 50% of the nominal power.

- Programming mode for the reduction level: microswitches / pilot cable

- Powerloss (W) < 5% Nominal Lamp power (nominal power and reduced power)

- Design voltage (V): 230

- With tolerances for performance (V): 190 - 253

- Mains frequency (Hz): 50 / 60

- Power factor (nominal power) > 0,95

- Earth leakage current per ballast (mA) < 0,5

- End of lamp life protected.

- Ambient temperature range (°C): -20…+50

- IP protection (min): IP 40



35

Centralized management systems.

The objective of these systems is to reduce the maintenance costs and

consumption of the equipment.

There are many different types of management systems. The most up-to-date is

made up of the following units:

- Light source unit. It gathers information regarding the condition of the

lamp (and measures its arc voltage), about the auxiliary devices and

about the opening of the support door (if it exists), and transmits this

information to the control box.

- Control box unit. This measures the supply voltage, strength, active and

reactive power, energy consumption (daily and accumulated). It

controls the ignition and shut-down of the installation. It transmits and

receives information from the remote control unit by means of

telephone modem, mobile telephone or radio.

- Remote control unit. This is a PC which features specific control

software. It receives information from the control box units and in turn

sends operating instructions back to these. It transmits daily breakdown

reports using the information it compiles.

It allows the installation’s operational parameters to be configured and

also to know the working order of different components at any time.

Using electronic ballasts, the illumination level can be regulated

between 20% and 100% (the lamp power can be regulated between

35% and 100%).

Due to the enormous variety of systems which are available, we cannot deal

with this type of control system in greater depth.

36


- The exterior lighting installation contract specifications should make a

request for an estimate of the energy consumption of the different

alternatives on offer.

- Lamps featuring high luminous efficacy and a long lifetime should be

installed. In general, sodium vapour lamps are to be used, or metal

halides lamps if a higher colour rendering index is necessary.

- Electronic ballasts are more efficient than the electromagnetic variety.

- Luminaires should feature a low upward flux performance (that is to

say, they should not emit light upwards), and an increased protection

index against water and dust, so that dirt cannot excessively diminish

their efficiency.

- The most efficient control of the ignition is carried out by means of

astronomic clock switches.

- In the majority of cases, the illumination level can be reduced during

the early morning hours, in order to carry this out, it is recommended

that a double level system including flux reducers at the series start be

installed.

A.2.3. Building indoor lighting (For more information regarding interior lighting, please turn to section B.2.6, for more information regarding lamps, please turn to Appendix I)

The importance of an adequate illumination in any type of environment is

fundamental and attends to two objectives:

- Good visibility.

- Visual satisfaction.

37

This chapter contains information regarding the equipment which is used in

lighting and which should be kept in mind not only when new installations are

carried out but also whenever there is a renovation. As part of the preparation

for this section, we have taken into account the compliances and approvals laid

out with respect to the maximum and minimum illumination levels which should

exist in each building depending on their use.

An illumination system should harmonize an appropriate illumination quality with

a rational use of energy, for this reason it is necessary to act during the design

phase (efficient design) and during the management and maintenance of the

installation (in accordance with the planned design phase).

Design phase: The design should be consistent with the necessary use,

introducing the most adequate technology. The equipment with the

lowest cost throughout its working lifetime should be chosen out of all

the different types of installations which fill these needs (all the total

investment and running costs during the lifetime of the lighting

installations should be compared).

Management and maintenance: A lighting installation can be made more

efficient by means of good management and maintenance. This

generally consists of carrying out a constant follow-up of the illumination

and of the security parameters.


The following points should be taken into account when designing an interior

lighting installation:

a) Space to be illuminated.

Spaces should be classified according to the visual activity to be carried

out: library, laboratories, offices, classrooms, swimming-pools,

corridors... the annual usage time and the natural light contribution they

include.

38

b) Recommended illumination parameters.

For each type of space there are recommended illumination levels which

should be followed:

Average illumination level (lux).

Colour rendering (Ra, IRC).

Glare rating (discomfort)

In the table below, we can see the recommended values for different types of

premises:

Type of room Average

illumination level (lux)

Glare rating* Colour rendering index (Ra, IRC)

Classroom General

300 B 70 - 80 Board

Computing classroom

General 500 A 70 - 80

Board 300 Graphic Design classroom

General 750 A 90 - 100

Board 300 Laboratory classroom

General 500 B 70 - 80

Board 300

Library Reading

area 500 B 70 - 80

Ambiental 200

Assembly hall General 200 C

70 - 80 Stage 700 --

Gymnasium General 300 C 80 - 90 Teachers’ lounge General 300 B 70 - 80 Cartography 700 B 70 - 85 Technical Design 700 B 80 - 90 Computer room 400 B 70 - 85 Secretary’s Office 500 B 70 - 85 Sales-Purchasing Department 500 B 70 - 85 Administration 500 B 70 - 85 Accounts Department 500 B 70 - 85

39

Publicity 500 B 70 - 85 Invoicing Department 500 B 70 - 85 Personnel Department 500 B 70 - 85 Legal and Finance Department 500 B 70 - 85 Calculus 500 B 70 - 85 Organization 500 B 70 - 85 Management and Executive Offices

500 B 70 - 85

Conference Room 300 C 70 - 85 Reception 300 C 70 - 85 Customer Service Offices 300 C 70 - 85 Laboratories 500 B 70 - 85 Workshops 500 B 70 - 85 Vaults 400 C 70 - 85 Archives 200 C 70 Switchboard 300 C 70 Mail 300 C 70 Kitchen 300 C 70 - 85 Auxiliary premises 150 C 70 Service Areas 150 C 70 Admission / Dispatch 150 C 70 Exhibition Hall 200 - 90 Demonstration Room 100 - 1000 - 90 Conference Hall 300 C 70 - 85 Waiting Room 300 C 70 - 85 Break Room 200 C 70 - 85 Cafeteria/Dinning Room 200 C 70 - 85 Changing Rooms 200 C 70 - 85 Corridors 150 C 70 - 85 Toilets 150 D 70 - 85 Store-rooms 100 D 70

*According to the CIE

Below we have included some recommendations for the design of facilities:

- Gather together similar activities in the same area and if this is not

possible, adopt an intermediate illumination solution.

40

- Those activities which require stronger illumination should be located in

areas which are nearer to natural light sources.

- In interior working areas, the most important factor is to provide adequate

illumination for the working plane.

A.2.3.2. Choosing equipment: lamps, luminaires, auxiliaries

In so far as choosing the adequate type of luminaire, lamp and auxiliary

equipment, first of all, it is necessary to determine the room which is the object

of the study, considering the activity to be carried out therein.

Lamps. In order to reduce costs (installation, operating and maintenance), the

choice of lamps should be made considering the following characteristics:

Colour rendering index: The higher the colour rendering index, the

greater the capacity to reproduce the “true” colour of objects.

Among those lamps which fulfil the recommended minimum colour

rendering for the activity to be carried out, the one featuring the

greatest efficacy (lum/W) and longest working lifetime should be

chosen.

Luminous efficacy (lum/W): Those lamps featuring a luminous

efficacy equal to or above 90 lum/W should be used. The greater the

luminous efficacy, the fewer the number of lamps and luminaires,

which means lower initial investment costs and lower operating costs.

Working Lifetime: The longer the lifetime the lower the maintenance

costs. It would be convenient to install lamps which have a lifetime

longer than 12,000 hours.

41

Below we have included a table to compare the different types of lamps which

can be used for exterior lighting, also indicating their recommended operating

field. The attached appendix also includes more information regarding lamps.

* CRI: colour rendering index. ** Due to the low efficiency of this type of lamp, it is only convenient for illumination during short periods. *** Taking into account the consumption of the system (lamp, antenna, HF generator)

With respect to colour temperature, the type of lamp to be used depends on the

activity which is to be carried out, as described in the table below:

Colour temperature of the lamp Activity

Warm tones: < 3,000 K

Rest areas.

Waiting rooms.

Recreational areas.

Neutral tones:

3,300-5,000 K

Spaces with a considerable natural light contribution.

Average visual scales.

Cool tones: 5.000 K High concentration visual scales.

Type of lamp Efficacy (lumen/W)

Working life (hours) CRI (*) Re-ignition Recommended use

Halogen (**) 13 to 25 2,000 - 5,000 100 Immediate Localized and decorative lighting

Fluorescent tubes 40 to 100 6,000 - 79,000 60 - 90 Immediate General

Compact fluorescent 65 to 90 6,000 - 15,000 80 Immediate General, localized

and decorative

Induction 65-80 (***) 60,000 80 - 89 Immediate General

Mercury vapour 35 to 60 8,000 - 16,000 50 - 60 10 minutes General

Metal halide 70 to 120 10,000 - 16,000 60 - 95 15 minutes General, localized

High pressure sodium vapour

66 to 150 12,000 - 18,000 20 - 65 1 to 15

minutes General

LED 10 to 20 100,000 75 - 80 Immediate Beaconing and signposting

42

Recommended technical specifications for interior lamps:

- CE Marking - Efficacy: ≥ 90 lumen/watt - Working lifetime: ≥ 12000 hours. - Colour rendering index: equal to or above that recommended for the type

of activity to be carried out.

In general terms, it can be said that in areas with a reduced height (less than 5

metres), it is convenient to install high performance fluorescent lamps, whilst in

higher spaces it is convenient to install high pressure sodium vapour lamps or

metal halide lamps.

Luminaires.

Luminaires are any type of equipment which distributes, filters or transforms

light emitted by one or by several lamps, which comprises all the necessary

components for the support, fixing and protection of the lamps and their

auxiliary equipment.

Luminaires are characterized by the following parameters:

Photometric distribution. According to the percentage of the

upward and downward flux (CIE): direct, semi-direct, direct-

indirect, semi-indirect, indirect.

Luminous efficacy.

Mounting system: ceiling, wall, surface,...

Degree of protection.

Electric classification.

Fulfilling specific compliances.

Among those luminaires which fulfil the glare rating (discomfort), those with the

highest efficacy should be chosen, as far as possible always using direct

illumination.

43

Recommended technical specifications for interior luminaires:

- CE Marking. - Compliances: EN 60598 - Class I or above. - Downward flux ≥ 70% - Glare rating: equal to or above the recommendation, depending on the

activity to be carried out. - Minimum IP:

Clean environments: 20 Dirty environments: 43

- Fulfilment of the specific compliance regarding the area in which they are to be installed.

Auxiliary equipment.

Incandescent lamps, halogen lamps (except the low-voltage variety) and

blended light lamps do not need any type of auxiliary equipment to be

connected to the mains, but discharge lamps require ballasts and some also

need ignitors: Below we have briefly summarised the different types of auxiliary

equipment for discharge lamps.

Fluorescent lamps:

These require an electromagnetic ballast, an ignitor and a condenser,

or on the other hand an electronic ballast which can substitute all

three elements.

High pressure mercury vapour lamps:

These require either an inductive ballast and a condenser in order to

compensate the power factor or otherwise an electronic ballast.

Metal halide lamps:

This type requires either an electromagnetic ballast, an ignitor and a

condenser or an electronic ballast.

44

High pressure sodium lamps:

This type requires either an electromagnetic ballast, an ignitor and a

condenser or an electronic ballast.

Ballast selection.

The energy efficiency of ballasts varies according to the type of ballast, the type

and power of the lamp, as well as the number of lamps associated to the

installation. In the table below we can see the percentage of power loss for this

equipment, in relation to the power of the lamp, depending on these factors:

BALLAST SELECTION

Type of lamps Type of ballast

Standard electromagnetic

Low-loss electromagnetic Electronic

Fluorescent 20-25% 14-16 % 8-11 % Discharge 14-20% 8-12 % 6-8 %

Low voltage halogen 15-20% 10-12 % 5-7 %

The 2000/55/CE directive regulates the energy efficiency requirements for

fluorescent lamp ballasts and classifies them into 7 efficiency levels, listed

below (from best to worst):

A1, regulated electronic

A2, low-loss electronic

A3, standard electronic

B1, very low-loss electromagnetic

B2, low-loss electromagnetic

C, moderate-loss electromagnetic

D, high-loss electromagnetic.

45

In general terms, we recommend the use of low-loss electronic ballasts or

regulated electronic due to the fact that they offer several advantages when

compared to the electromagnetic variety.

With regard to fluorescent lamps, it is convenient to use electronic ballasts

which include preheating (these are essential in lamps which are turned on

three times a day or more, otherwise the working lifetime of the lamp will be

drastically reduced).

DOSSIER FOR ELECTRONIC BALLASTS

Advantages:

A reduction in consumption of more than 25% with respect to the low-loss electromagnetic variety.

An increase in the efficiency of the lamp (fewer lamps have to be installed in order to obtain the same illumination level).



No condenser is needed to correct the power factor, given that the reactive energy demand of electronic ballasts is negligible with respect to the electromagnetic variety.

Elimination of the strobe effect (light intermittence). The quality of the light emitted by the lamp is increased (reduction of headaches and tired eyesight due to the flickering produced by electromagnetic ballasts).

General increase in comfort, eliminating any noise produced by the equipment.

A constant illumination level, not affected by variations in pressure throughout the day.

46


A reduction in the buildings’ thermal loads due to their reduced consumption.


The possibility to connect to direct current for emergency lighting.

Additional advantages of regulated electronic ballasts:

Greater comfort, as they enable the illumination level to be adjusted according to need.

They can be connected to light sensors in order to automatically adjust the intensity of the light emitted by the lamp depending on the level of natural light, thus maintaining a constant overall level of light.

A reduction in consumption of up to 70% with respect to a system using electromagnetic ballasts.

Disadvantages:


Additional costs:

Below we have included additional costs and the return period for the additional investment with respect to a low-loss electromagnetic ballast (including installation and VAT): (average values for 4,000 hours of operation per year).


Low-loss electronic ballasts (A2) for fluorescent lamps 18 euros 2 years

Regulated electronic ballasts (A1) for fluorescent lamps 60 euros 4 years

Electronic ballasts for metal halide lamps 100 euros 6 years

47

Electronic ballasts for high pressure sodium vapour lamps 100 euros 6 years

Technical specifications for ballasts:

- Compliances and approvals


(radiated) EN 55022 class A

- Immunity EN 61547 - Humidity EN 60068-2-3-Ca - Safety EN 60926 / EN 60928 (electromagnetic ballasts EN

60922) - Harmonics EN 61000-3-2 - Performance: EN 60927 / EN 60929 (electromagnetic ballasts EN

60923) - Vibration & bump tests: IEC 68-2-6 FC, IEC 68-2-29 Eb - CE marking.

- Powerloss (W) < 10% Nominal Lamp power - Rated mains Voltage (V): 220 - 240 - With tolerances for performance (V): 202 - 230 - 254 - With tolerances for operation (V): 198 - 230 - 264 - Mains frequency (Hz): 50/60 - Power factor (nominal power) > 0.95 - Earth leakage current per ballast (mA) < 0.5 - End of lamp life protected. - Ambient temperature range (°C): -15…50 - Failure rate at nominal case temperature (%/1000h): 0.35 - Lifetime at nominal case temp.(Max. 5% failures) hours: 60,000 - Overvoltage protection: 48 hr at 320 V AC, 2 hr at 350 V AC

48

A.2.3.3. Lighting regulation and control systems

The installation of control systems reduces the energy and maintenance costs

of the equipment and also increases the flexibility of the illumination system.

This control means that selective ignitions can be carried out and that the

luminaires can be regulated during different periods of activity, or depending on

the varying type of activity, and this can mean an energy saving of up to 65%.

There are four fundamental types:

Regulation and control by the user by means of a manual switch,

button, potentiometer or by remote control.

Regulation of artificial light depending on the amount of natural light.

Switch on and off depending on physical presence.

Regulation and control by means of a centralised management

system.

a) Illumination control by means of manual or timed switches.

A manual control by the user is a good and simple tool, but unfortunately it does

not tend to work well (many times the lights are left on unnecessarily).

Whenever manual switches are used, it is worth following this advice:

- The switches should be labelled, indicating which installation or circuit

they operate.

- The switches should not be placed closely together to avoid users

activating several switches with just one movement of the hand.

- Those luminaires which are close to windows should be controlled

independently from the others.

- It is advisable to limit as much as possible the number of luminaires

controlled by each switch. In a room or a hall, the number of switches

should not be lower than the square root of the number of luminaires

which are installed.

49

Timer switches can be used in those rooms where the presence of people is

limited to a short period of time (for example, toilets).

Programmable switches (using daily or weekly programmes), can be used to

switch off lamps from the mains control unit during those periods when the

facilities are not being used.

b) Artificial lighting control by means of natural light controllers.

In the majority of premises, natural light can be used up to a distance of about

four metres away from windows and during most of the year, thus allowing the

use of luminaires installed in these areas to be reduced.

This control system is based on a light sensor which is usually placed on the

ceiling, it measures the quantity of natural light entering the room and enables

the level of artificial light to be adjusted accordingly in order to maintain a

uniform lighting level.

There are two types of regulation system:

- All / nothing: the luminaires are turned on or off depending on whether

a predetermined illumination level is surpassed or not. The system

should feature a certain inertia to avoid turning lights on and off

because of temporary variations in the natural light. This control

system may be bothersome for users.

- Progressive regulation: the illumination is progressively adjusted

depending on the contribution of exterior light in order to maintain the

predetermined lighting level. This is achieved simply by regulated

electronic ballasts controlled by a photocell.

We recommend installing progressive regulation systems for all those

luminaires located close to windows and in any areas where the level of light

needs to be adjusted depending on the activity being carried out at any given

moment (for example, meeting rooms).

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c) Artificial light control by means of presence detectors.

Presence detectors turn off any artificial illumination whenever there is nobody

in the room they control.

There are four types of detectors: infrared, ultrasound, microwave, and

ultrasound-microwave hybrids.

This system is recommendable for areas which are intermittently occupied,

such as toilets.

d) Regulation and control by means of a centralised management system.

Advantages of this system:

- It is possible to switch areas on and off by means of centralised

commands, either manually or automatically (turning off during

periods when the premises are not in use).

- Lighting circuitry can be modified without carrying out any electrical

works (only the programme is modified).

- The status and consumption of different circuits can be controlled.

Any type of centralised control should also feature simultaneous local control.

51

Additional costs

Below we have included additional costs and the return period for the additional investment in lighting regulation and control systems (including installation and VAT): (average values for 4,000 hours of operation per year).


Presence detector 30 euros 2 years

Regulated electronic ballast (A1) + photocell (regulation depending on the quantity of natural light)

65 euros 4 years

Timer switch 80 euros 4 years

Programmable switch 90 euros 3 years An example of a centralised management system for the illumination of an

office building by means of a local control system.

The system is made up of a network of intelligent components which

communicate with each other via a double cable bus (EIB...), which eliminates

the need for a central control unit, and also considerably limits the area

affected by a failure in the system.

The devices in the system are classified into three categories:

- Sensors: these are the infrared receptors, movement detectors, light

sensors and system clock. They transmit status messages via the

bus.

- Actors: they translate the status messages into outputs for the light

controllers.

- Generic network management tools: routers, repeaters, bus power

sources, and interface cards for the computer.

52

A.2.3.4. Maintenance

As time goes by, dirt will slowly be deposited on the luminaires and along with

the reduction in the luminous flux of the lamps, this will make the initial

illumination level decrease considerably.

The initial illumination level values can be restored by regularly cleaning the

luminaires and by changing the lamps once they have reached the end of their

lifetime.

Furthermore, windows should also be cleaned so as to maintain the

transmission of natural light. This principle also applies to the surfaces of

ceilings and walls in order to maintain their reflectance.

When carrying out a lighting project, one should take into account the reduction

of luminance brought about by dirt between cleaning periods: a depreciation

factor should be applied depending on the frequency of the maintenance carried

out on the facilities.

In order to reduce this depreciation, it is advisable to install dustproof luminaires

in premises with a high degree of contamination.

Recommended reflection factors.

Reflection

Walls 0.5-0.7

Ceilings 0.7-0.8

Floors 0.15-0.20

Furniture and equipment 0.20-0.40

Curtains 0.50-0.70

53


- When designing a lighting installation, the illumination level in each area

should be adapted to the activity which is to be carried out, above all

making it appropriate for the working area.

- The equipment should be adequately sectioned off in order to avoid

energy consumption in areas that are not in use.

- Lamps featuring high luminous efficacy and a long lifetime should be

installed. In general, high performance fluorescent lamps should be

used for heights under 5 m, and high pressure sodium vapour or metal

halide lamps for greater heights.

- Electronic ballasts are more efficient than the electromagnetic variety.

With regard to fluorescent lamps, it is convenient to use electronic

ballasts which include preheating.

- Luminaires should feature a low upward flux performance (that is to

say, they should not emit light upwards).

- It is convenient that lights be turned on automatically in areas where it is

not absolutely clear who is responsible.

- Progressive regulation systems should be installed in all those

luminaires which are close to windows.

A.2.4. Office automation equipment

In today’s society the presence of computer systems in offices is essential.

Anybody who carries out technical or administrative tasks at work has a

computer as a basic working tool, and all of this contributes to the energy

consumption of buildings, not only in a direct manner due to the consumption of

the devices themselves, but also because of the increase in the thermal load

associated to them (an increase in the energy consumption of air conditioning

systems).

54

Approximately 4% of the electricity which is consumed in the services sector is

due to the consumption of office computer equipment, even though this figure

could be increased to more than 20% in the case of an administrative building.

Personal computers are responsible for 55% of the total consumption of

electricity, and the rest corresponds to printers, photocopiers, fax machines and

other auxiliary services.

It is useful if the equipment which is available has a “bookmark” or marker shut-

down system. These systems allow the user to disconnect the equipment by

means of a sequence of appropriate keys, saving the last position before being

switched off; as a result, when the user reboots the device, it starts up at the

same position at which it was left before being turned off.

A.2.4.1. Recommendations for the acquisition of computer equipment

Those responsible for buying office computer systems are recommended to

purchase devices which feature energy saving characteristics. Suppliers should

be asked to provide equipment which has been identified by the manufacturers

by means of easily recognisable logos indicating their energy saving

characteristics.

They should also include clear instructions regarding their installation and

configuration, as well as their compatibility with other devices and software. The

packages should also be provided with drivers that are compatible with the

Linux open source operating system.

Computers should hold the “Energy Star” logo from the EPA (Environmental

Protection Agency) which makes reference to the devices’ capacity to shift into

a standby mode after a specific period of time, a mode in which the power is

reduced to less than 10% of the nominal power.

55

The size of the equipment also considerably influences its energy consumption,

therefore it is necessary to assess the realistic need for a computer and to

choose one which is powerful enough to satisfy these. This is mainly applicable

to monitors, because their consumption is closely linked to their size.

Computer acquisition. Any computer equipment acquisition order form should specify that the devices

have to incorporate energy saving systems (Energy Star compliance), the

appropriate programmes and the precise documentation in order to set up the

configuration simply.

They should also include a list of SCSI systems which are incompatible with the

energy saving systems (scanners, disc burners, etc).

Printer acquisition.

Printers and photocopiers are the most energy consuming devices in any office

and both of these are idle for most part of the day. This is why it is essential that

printers include energy saving systems so that they can reduce their

consumption to a minimum during these inactive periods (Energy Star

compliance).

Any printing equipment that is acquired should include a double sided printing

feature which would save both paper and energy.

The equipment should include detailed instructions so that it can be configured

correctly and also drivers for Linux.

Photocopier acquisition. The photocopier should include an energy saving mode (Energy Star

compliance) as well as a double sided printing option.

56

The acquisition of other equipment

The consumption of any other type of office computer equipment, such as

scanners, fax machines, modems, etc, is much lower, but even so they should

be acquired including energy saving systems (Energy Star compliance) and

drivers for Linux.


- The acquisition form for the purchase of office computer equipment

should demand energy labelling such as “Energy Star”, furthermore,

any bidder who certifies that they have offered high efficiency

equipment should be given priority.

- It is advisable to purchase equipment which has bookmarker shut-down

features, allowing the last position to be saved and to be recovered

when the computer is rebooted.

- TFT monitors consume much less energy than tube monitors.

Moreover, unjustifiably large monitors should not be purchased.

- Printers and photocopiers should include a double sided printing option,

which would contribute to saving paper and therefore also saving

energy.

A.2.5. Boilers and air conditioning equipment (for more information regarding heating and water installations, please turn to

section B.2.3,

for more information regarding cooling system installations, please turn to

section B.2.4.,

for more information regarding ventilation system installations, please turn to

section B.2.5).

57

Before defining the most appropriate equipment for a specific type of building it

is necessary to determine the environmental conditions which the users require,

which will fundamentally depend on the characteristics of the building which is

to be acclimatized (shape, size, type of enclosure, orientation, use,...) and the

hot water needs which its use may bring about.

Any acclimatization installation basically consists of:

- Generator equipment – transmitting thermal energy to a fluid.

- Fluid transport network.

- Thermal energy environment transfer unit.

In this section of the guide we will mainly be making reference to the generator

equipment.


In order to reduce the consumption of acclimatization equipment it is necessary

for the constructive characteristics of the building to be adapted as far as

possible to the exterior environmental conditions and for there to be an

appropriate distribution of the rooms according to their use.

When designing thermal conditioning installations it is essential to keep in mind

the degree of occupation and the function of the rooms in the building. To this

respect, it is necessary to use systems which can control the way in which the

installation works depending on the demands at any given moment and in any

given area or rooms, which means that the appropriate system should include

the following characteristics:

Variable ventilator speeds.

Variable pump speeds to push the heat carrying fluids.

Control system zoning.

Automatic regulation of predetermined temperatures.

58

Another characteristic which should be included as part of the acclimatization

system is, on the one hand the incorporation of mechanisms for the recovery of

heat which is held in eliminated air, thus enabling the energy consumption

associated to air renewal to be reduced, and on the other hand, free cooling

systems, which cool by using air from the outside whenever the temperature is

lower than inside (this reduces the operating times of the cooling equipment).

A central control system should also be included in order to be able to draw up

an operating plan for the equipment (to plan the start-up and shut-down of

compressors, ventilators and circulation pumps), in order to avoid operating the

equipment during those periods when the building is not in use (nights,

weekends).

In order to avoid energy losses, it is necessary to install switches on windows

so as to put the system in stand-by whenever these are open.

Similarly, the system will have to maintain the temperature of different areas

within certain comfort levels determined by users and, in general, it should be

able to meet the heating and cooling needs simultaneously.

Distribution losses should be limited by insulating piping (the economic

insulation should be calculated according to the price of the energy to be used,

the insulation costs and the operating time of the equipment).

A prevention plan should be drawn up and put into practice, including the

following points:

Cleaning of condensers (exterior units) because any obstruction

diminishes their efficiency.

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Cleaning the evaporators (interior units) or interior transfers units.

Cleaning and replacing filters.

Verification of electric connections.

Verification of piping insulation.

Verification of the working order and condition of the generating

equipment (circuit temperatures and pressures).

Now that we have indicated the general standards to be met by acclimatization

systems, we can focus on the specific characteristics of different heating and

cooling systems which can be installed in a building, even though they can be

one in the same.

Choosing an acclimatization and hot water system

The choice of the acclimatization and hot water system first of all will depend on

the energy sources which are available in the area, and secondly on the

profitability of those which can be used.

It is extremely difficult to establish general criteria that can be applied to all

European regions, due to the fact that the energy sources which are available in

any given area are different, as well as the prices which correspond to these.

For this reason, in order to determine a central heating and acclimatization

system, it is convenient to contract a company specialized in energy

consultancy to carry out a comparative study of the different alternatives. The

system which is chosen should be that which has the lowest costs throughout

the equipment’s working life, keeping in mind the depreciation of the initial

investment.

A.2.5.2. Choosing equipment Below we have indicated the different types of equipment that can be used as

generating units.

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A.2.5.2.1. Heating equipment (For more information regarding central heating installations, please turn to section B.2.3) Boiler.

The main function of this piece of equipment is to transfer to the water the heat

liberated by the combustion of a solid, liquid or gas.

Standard boilers.

Standard boilers ensure that the temperature of the return flow (the water

entering the boiler) is higher than 60ºC, in order to avoid the appearance

of acids which are present in the combustion gases and thus prevent

their corrosion.

The performance of this equipment is approximately 90% above the ICP

(inferior calorific power), in the case of gas combustion this is slightly

higher and lower for solid fuels.

There are two special types of boilers which have a higher efficiency than the

standard variety: low temperature and condensing boilers.

The 92/42/CEE Council directive of 21st May 1992 concerning the performance

requirements for new hot water boilers powered by liquid or gas fuels, defines

this type of boiler as follows:

Low temperature boiler: a boiler that can work continuously with a

feedwater supply temperature between 35 and 40 °C and which may

produce condensation in specific circumstances (without affecting the

boiler itself); these include condensing boilers which use liquid fuels.

The performance of these boilers is higher than 93% (above the ICP).

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DOSSIER FOR LOW TEMPERATURE BOILERS

Advantages:

They can run with low water return flow temperatures (35ºC) without producing condensation and without damaging the boiler.

They can regulate the temperature of the water flow depending on the environmental conditions and the heating requirements, which means a reduction in consumption.

Less maintenance. There is no need for an anticondensation pump and the materials which are used, have a longer working life.

Less fuel consumption. When compared to a conventional boiler, the reduction in fuel consumption is greater than 5%.

Disadvantages:

Higher price than that of a conventional boiler.

Additional costs:

Below we have included additional costs and the return period for the additional investment with respect to a conventional boiler (including installation and VAT): (average prices for 2,000 hours of operation per year).


Low temperature boiler + 43% 3 years

Recommended technical specifications for low temperature boilers

- Fuel: gas / diesel oil - Modulating burner. - Minimum performance: ≥ 93%

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Condensing boiler: a boiler designed to be able to permanently

condense a significant proportion of the water vapour which is

present in the combustion gases;

Using the condensation technique means that the boiler can recover

the latent heat from the water vapour which is present in the

combustion gases and therefore achieve an efficiency higher than

110% above the Inferior Calorific Power (ICP).

DOSSIER FOR CONDENSING BOILERS

Advantages:

They can run with low water return flow temperatures (40 - 30ºC) without damaging the boiler.

Their performance improves when the load is reduced. Unlike conventional boilers, with which the opposite occurs.

Less fuel consumption. When compared to a conventional boiler, the reduction in fuel consumption is greater than 20%.

Disadvantages:

Higher price than that of a conventional boiler and than a low temperature boiler.

Additional costs:

Below we have included additional costs and the return period for the additional investment with respect to a conventional boiler (including installation and VAT): (average prices for 2,000 hours of operation per year).


Condensing boiler + 350% 6 years

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Recommended technical specifications for condensing boilers

- Fuel: gas / diesel oil - Modulating burner. - Minimum performance:

With full load: ≥ 106% With a 30% load: ≥ 109%

In order to increase the efficiency of an installation with boilers and to obtain a

greater degree of control, is it advisable to use modulating boilers and to divide

the total necessary power between several units (several boilers are better than

just one).

Heat pump

A heat pump is a machine which is designed to heat or cool a space by means

of an external source with a temperature that may be lower or higher than the

space to be heated or cooled respectively.

In order to carry out both functions (heat or cool) the equipment should be

reversible heat pumps, that is to say, they invert their working cycle and change

from producing heat to cold, whenever the need may arise.

The basic components of a heat pump are the following:

Compressor.

Transfer unit (condenser or evaporator depending on the cycle).

4 way expansion valve.

The source from where the heat is taken is called “heat source” and the place to

which the heat is transferred is known as the “heat sink”. Pumps are classified

depending on the type of heat source and heat sink as follows:

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Air to air heat pumps: The heat source and heat sink are air. This type

of pump is the most common, mainly in acclimatization.

Air to water heat pumps: These are used to produce cold water for

refrigeration or hot water for central heating or sanitation, transferring or

taking energy from the exterior air.

Water to air heat pumps: They make the most of the energy which is

held in the water in rivers, seas, etc. Their energy efficiency is better than

those using exterior air, due to the greater uniformity of the temperature

of the water throughout the year.

Water to water heat pumps: These are similar to the previous variety,

except that they pass energy to a water circuit which is then transferred

to the environment by means of low temperature radiators, fan-coils or

radiant flooring.

Ground to air and ground to water heat pumps: These make the most

of the heat which is present in the ground. They are not very common,

due to their high cost.

Depending on the thermal load to be considered, there is a wide range of

heating powers in this type of equipment. In order to select a model, the

greatest thermal load which can be demanded by the building has to be

determined, albeit in terms of heating or refrigeration. This equipment can

reach an OC (operating coefficient) above 4, that is to say, for each kWh

consumed by the heat pump, it supplies four in either heating or refrigeration.

Storage heater

A storage heater is a device which works by using electric elements to generate

thermal energy at night (during those hours when electricity is cheapest) and

storing it in a heat-resistant material; this material can accumulate the heat in

order to later deliver it throughout the day into the area which is to be heated,

conditioning it to the desired temperature.

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Parts of a storage heater:

Thermo-accumulating nucleus: made up of heat-resistant material bricks,

with an increased specific heat capacity and high density, so as to easily

store energy. The temperatures they can reach range between 600 ºC

and 700 ºC.

Thermal insulation: this surrounds the nucleus and limits the surface

temperatures that can be reached.

Electric elements: made of stainless steel with magnesium insulation,

they are located inside the nucleus. They can reach temperatures around

900 ºC.

Safety components or Thermal Limiters: these are used to avoid any

possible excessive or anomalous increases in temperature. They are

independent from the storage thermostat and the room thermostat.

Connection and control elements: their function is to regulate the heat

storage and output.

Casing: where all the storage heater’s accumulation elements are

housed. They are usually made of galvanized steel and adapted to the

surroundings in so far as shape, colour, size, etc.

Storage heaters can be classified into the following types:

Static: the heat is given off via the internal surface and by natural

convection.

Standard static: these give off thermal energy by means of

radiation principles.

Conventional static: besides using radiation, there is also

convection through an air inlet at the bottom and outlet at the top.

These are controlled by a cover plate. The heat can be released

manually, or automatically depending on the interior temperature

of the room (using a remote control that works the plate).

66

Static compensation: these are a mixture of the standard static

storage heaters and traditional convection heaters as back-up.

This is the least recommended system due to its higher operating

costs.

Dynamic: in this type of equipment a current of air is forced through

the inside by means of a ventilator. They offer greater heating

powers than the static variety.

The most typical distribution of these devices is the following:

• Static storage heaters in rooms where a constant temperature is

required or with little variation (for example, corridors or waiting

rooms)

• Dynamic storage heaters in rooms where considerable variations in

temperature are needed (for example, halls and libraries) due to any

possible energy contributions from other sources (such as people,

sun, etc).

STATIC STORAGE HEATERS

ADVANTAGES DISADVANTAGES

Low price (150 – 200 euros/kW).

Simple installation.

They help to stabilize the country’s electric load curve (they increase demand during low peak periods)

Fewer regulation options (only for the conventional type)

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DYNAMIC STORAGE HEATERS


Low price (160 – 300 euros/kW).

Simple installation and regulation.

They help to stabilize the country’s electric load curve

High price for low heating power (300 euros/kW).

RECOMMENDED STORAGE HEATER FOR EACH ROOM

STATIC DYNAMIC

Entrance halls

Reception

Administration

Secretary’s Office

Waiting rooms

Classrooms

Libraries

Offices

Meeting rooms

Plenary meeting halls

Assembly halls

In general, a central heating system using storage heaters seems interesting in

all those buildings where the heating consumption is reduced.

Storage boiler

This system is similar to the previous example, but it uses water as the heat

transfer source instead of air. There are two types of storage boilers:

Dry storage. The nucleus where the thermal energy is stored is made

up of heat-resistant bricks, which heat the water in the central

heating circuit via a heat exchanger.

Wet storage. The nucleus is made up of water accumulators where

the water is heated.

The final heat exchanger units are water radiators.

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Radiant panelling

This consists of using the floor, walls or ceilings as thermal energy

accumulation elements. The installation consists of distributing electric elements

throughout the entire surface.

Nowadays, this is a rather uncommon system due to the fact that the energy

accumulation capacity is low, which means that operating costs are high (not

enough energy can be stored at night for it to work during the day).

Furthermore, problems usually appear in time because of the need to replace

some elements, which is difficult and expensive.

Radiant floors

This consists of a network of pipes running through the floor of the premises

which contain hot water at a low temperature (40-45 ºC) from a boiler, a heat

pump or from a solar heat accumulator installation.

The water transfers heat to the floor via the pipes, and from the floor it moves

into the environment. The pipes are made of a plastic material, corrugated

polyethylene is usually employed.

This is the system by which the heat transfer is carried out in what seems to be

the most adequate way, from bottom to top, and uniformly throughout the

surface of the room which is being acclimatized.

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RADIANT FLOORS


Cleanliness: by eliminating any humidity in the floor, it stops the reproduction of microbes, mites and fungi.

Hidden system: it cannot be seen and it does not take up any space.

It is very adequate for large surfaces and wherever there are high ceilings.

It does not create air currents.

Minimum maintenance.

With a heat pump it can be used to cool in summer.

It can be used to make the most of solar energy (heat proceeding from solar energy heat accumulators)

High price.

Specialized personnel is required so that no installation problems arise.

High thermal inertias which reduce the response time and make it difficult to control.

Little flexibility in terms of distribution changes.

Solar heat accumulators

Thermal solar energy makes the most of sunlight to heat a fluid, in most cases

water. A system of this type consists of one or more solar heat accumulators

connected to a circulation circuit which transports the fluid at the desired

temperature to the point where it is used.

In a building it can be used to heat hot water for sanitation, as a back-up for the

conventional central heating system, to heat the water in swimming pool, or

even for refrigeration by means of an absorption machine.

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SOLAR HEAT ACCUMULATORS


Very low operating costs.

Allows Co2 emissions from acclimatization and hot water demands to be reduced.

Considerable investment and return periods.

It requires a large absorption surface positioned facing close to south.

A solar heat accumulation system is made up of three subsystems:

a) Solar accumulators.

There are three types

1. Glassless panels: appropriate for temperatures which are not very

high, such as swimming pool heating. They are cheap and simple.

2. Flat panels: appropriate for hot water for sanitation and central

heating for houses, as well as for districts, given that the majority

produce temperatures of up to 70 ºC. They are the most common

variety.

3. Vacuum insulation panels: appropriate for high temperature

applications because they can heat water up to 90-100 ºC.

b) Circulation systems

These are responsible for transferring the heat from the collector to the point

where it is used.

c) Control systems

They make sure that the system operates efficiently and that it maintains the

desired temperature at the final exchange point. They consist of temperature

sensors which provide information regarding the status of the system and a

central unit which monitors the running of all the equipment.

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A.2.5.2.2. Cooling equipment (For more information, please turn to section B.2.4) A room can be cooled by means of refrigerating machines, or similarly a

reversible heat pump operating in cooling mode. In order to cool a building,

there are two possibilities: either using independent units in each room, or using

a centralized system for the whole building. Independent units are better at

cooling one or two rooms in climates where there are few very hot months a

year. Centralized refrigeration systems can save installed power with respect to

the equivalent independent units, as well as making any maintenance easier.

There are three types of refrigeration systems: an air cooling system, a water

based cooling system and a direct expansion system to circulate a refrigerating

liquid throughout the premises.

Air cooling system.

This consists in cooling the air with a central cooling unit and distributing it

through the entire building by means of pipes. A cold air flow conduit is

necessary in each room as well as another to return the warm air which is in the

rooms (they should be well insulated so as to avoid increased energy losses).

The air enters the rooms through grills or diffusers.

CENTRALIZED AIR COOLING SYSTEM


Air is cooled quickly, so it is very adequate for large capacity premises or those with an increased internal thermal load.

It can also include a battery module to heat air in winter.

A free cooling system can be included: if the temperature outside is lower than inside, air from the outside can be introduced directly without wasting energy to cool it.

Space necessary to install the air conduits (large sections).

Little flexibility if use by zones is required.

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Water based cooling system

This consists of cooling water by using a central cooling unit and distributing it

through the entire building by means of insulated pipes (a cold air flow conduit

and return pipe). In each room there is a battery module to cool the air using

water (a fan-coil type water-air interchanger).

CENTRALIZED WATER BASED COOLING SYSTEM


The system can also be used for central heating either by including an additional interchanger to heat the air in winter (four-tube system: two for cooling and two for heating) or by means of a reversible heat pump (two –tube system).

It allows the acclimatization of each room to be precisely controlled.

The presence of a convector in each room increases any maintenance costs: cleaning and filter replacement, etc.

The ventilator produces noise when in operation (the ventilator is necessary to circulate the air which is to be heated through the water-air interchanger).

Direct expansion system

They are low power systems which are used to condition rooms of up to 100m2

in size.

These air-conditioning systems for one room (“room air-conditioner” RAC) are

classified as follows:

Compact split and multi-split units.

The split system consists of a unit located outside (the condenser unit

which transfers heat into the environment) and another placed inside (the

evaporator, which takes heat from the surrounding air).

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Multi-split units are made up by several interior units connected to an

exterior unit.

DIRECT EXPANSION SYSTEMS: SPLIT AND MULTI-SPLIT


Highly efficient.

Good temperature control by equipment which features “inverter” technology (cooling power is regulated by means of adjusting the rotation speed of the compressor) which can generate an energy saving of save up to 30% in energy consumption with respect to traditional units.

It is possible to include central heating which avoids duplicating systems (a reversible heat pump only costs 10% more than a cooling unit).

The interior units generate noise in the room which is to be acclimatized.

Compact individual units.

Low power equipment (<10 kW) in which the evaporator, compressor

and condenser are assembled in a single structure (one side of the

device – the condenser – is in contact with the outside, whilst the other

side – the evaporator – is in contact with the room). This type of

equipment is usually installed in the windows of those rooms to be

acclimatized.

Both sides of the machine are separated by a dividing wall, which is

insulated in order to avoid the transference of heat between the two

spaces.

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DIRECT EXPANSION SYSTEM: INDIVIDUAL COMPACT UNITS (Window units).


Easy installation They generate noise in the room which is being acclimatized (the compressor and the ventilator) –more than the split variety – .

Low efficiency.

A.2.5.2.3. Ventilation (For more information regarding ventilation systems, please turn to section B.2.5) Ventilation is necessary in any premises in order to maintain a healthy

environment, that is to say, introduce clean air from the outside to refresh the

dirty air inside which contains a high concentration of subproducts of human

activity (sweat, carbon anhydride, chemical compounds which are given off by

furniture and by other elements which make up the building).

Depending on the activity, there are recommended ventilation values depending

on the type of activity which is carried out in the room. These values are

established in the directives of each country and should be followed when

calculating and carrying out any air renovation.

The ventilation of any premises can be natural or forced.

Natural ventilation is any type of ventilation which can be achieved without

having to use energy and is carried out by leaving doors, windows, etc, open,

communicating the room with the outside.

Forced ventilation uses ventilators in order to carry out the renovation of air

(using the ventilators, air from the outside is pushed into the premises).

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NATURAL VENTILATION


Does not require energy Insufficient if there are more contaminating points in the room than occupants.

Difficult to regulate (the renovation depends on the meteorological conditions and of the surface of the openings to the outside).

FORCED VENTILATION


Easy to regulate (the renovation rate is easily adjustable and controlled).

Can be applied to the building’s interior rooms (with no direct communication with the outside)

Requires energy

In case there is a highly contaminating incident in some area of the premises

which are to be ventilated, it is necessary to carry out a localized extraction to

capture the smoke, dust, vapours, etc, in order to avoid any further

dissemination through the environment.

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- When designing acclimatization installations, the systems to be chosen are those

which are highly efficient at partial loads, which can be maximized by centralized

systems.

- The most efficient technology used to generate heat for central heating are

geothermal heat pumps and high efficiency boilers (low temperature or

condensing).

- The areas to be acclimatized should be divided into zones, and measuring,

regulating and control devices should be installed in each area, so as to adapt the

environmental conditions to those required, avoiding any irresponsible practices

by users.

- The design of the building on the whole should try to avoid thermal loads in

summer months, providing elements for protection from the sun, such as

awnings, blinds, curtains, and reducing the internal load by using high efficiency

bulbs,...

- The most efficient types of technology are those featuring mechanical

compression with an electric motor or direct absorption cycles in those cases

where there is not enough electric power available, or for example, if the objective

is to flatten the natural gas consumption curve throughout the year.

- The building project should provide for the insulation of heat and cold

transmission conduits.

- The areas to be cooled should be divided into zones, and measuring, regulating

and control devices should be installed in each area, so as to adapt the

environmental conditions to those required, avoiding any irresponsible practices

by users.

- The cooling system should allow the enthalpy of the outside air to be harnessed.

Furthermore, it should allow the energy from the renovated air to be harnessed

by means of regenerating systems.

- Furthermore, the ventilation system should allow the ventilation flow to be

regulated depending on the occupancy level.

- It is recommendable to limit the number of openable windows in those areas

where there is artificial ventilation.

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A.2.6. Official vehicles, refuse collection and public transport In the following section we have analysed the acquisition of vehicles for public

administrations.

A.2.6.1. Light vehicles Since 1992 the European Commission has approved several directives which

establish the energy efficiency requirements of different types of energy

consuming equipment, and this is detailed in their energy labelling.

Energy labelling classifies equipment in to seven different groups, and each of

these are represented by a letter (A, B, C, D, E, F, G), “A” being the most

efficient and class “G” the most inefficient.

The objective of the 1999/94 CE Directive, published in the Official Journal of

the European Communities of 18th January 2000, is to inform about the fuel

consumption and CO2 emissions of new cars, so that consumers can consider

acquiring more efficient cars. Taking this directive into account, as well as its transposition to the legislation of

each country, when renewing different vehicles it is recommended that the

energy labelling be considered as a reference to their fuel consumption and

polluting emissions and that vehicles featuring energy label “A” be bought.

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DOSSIER FOR VEHICLES FEATURING ENERGY LABEL “A”

Advantages:

Low consumption: they are the most efficient in their class. For each type of vehicle (utility, saloon, ...) there are several models with an “A” energy label, which feature the lowest consumption.

Lower operating costs due to their lower consumption and lower acquisition costs due to the fact that they have more moderate engine power.

Disadvantages:

None.

These are cheaper vehicles than the less efficient variety, therefore their acquisition is justified not only from an economic but also from an energy point of view

Recommended technical specifications for motor vehicles with internal combustion engines (petrol or diesel).

- Energy classification “A”. - Sensible average consumption:

Small vehicles (< 3.75 m) - Petrol: ≤ 5 litres / 100 km - Diesel: ≤ 4.5 litres / 100 km

Saloons and medium estates (< 4.5 m)

- Petrol: ≤ 6.5 litres / 100 km - Diesel: ≤ 5 litres / 100 km

Saloons and large estates (> 4.5 m)

- Petrol: ≤ 8 litres / 100 km - Diesel: ≤ 5.5 litres / 100 km

Medium people carriers (< 4.5 m)

- Petrol: ≤ 8 litres / 100 km - Diesel: ≤ 6 litres / 100 km

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Large people carriers (> 4.5 m) - Petrol: ≤ 8.5 litres / 100 km - Diesel: ≤ 7 litres / 100 km

Small vans (< 4.5 m) - Petrol: ≤ 6.5 litres / 100 km - Diesel: ≤ 5.2 litres / 100 km

Large vans (> 4.5 m) - Petrol: ≤ 10 litres / 100 km - Diesel: ≤ 8 litres / 100 km

There is a progressive tendency to use heavier and more powerful vehicles, in

most cases to move just one person, and on many occasions for short journeys

limited to small geographic areas.

When buying one or several vehicles it is convenient to analyse their most likely

use. If what is necessary is a car to move around the local area and

surroundings in order to attend meetings, it is recommended that a small car be

purchased, both in terms of weight and engine power (less than 70 cv). This

vehicle will be easier to drive and to park at the destination and it will also

reduce the energy consumption drastically.

When either the destination of a journey is unknown or the itinerary needed to

get there, it is recommended that any car which is purchased be fitted with a

navigation system, because they contribute to the optimization of journeys by

reducing the time taken and distance covered, and as a result also the energy

consumption.

Nowadays, there is a series of well-known driving techniques which drastically

reduce energy consumption whilst driving. These basically consist of making

the most of the vehicle’s inertia and driving at low revolutions. As a measure to

contribute to teaching oneself these measures, and so as to reinforce any

knowledge that has been learnt, it is recommendable to purchase vehicles

which include instant consumption information screens.

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These features indicate at all times the consumption per one hundred

kilometres at the current driving speed, which can contribute to an increasingly

more efficient driving style. Moreover, these efficient driving techniques

contribute to a slower deterioration of the vehicle.

Another complement which is considered interesting are those mechanisms

which control the car’s speed (Cruise Control). They enable the driver to

programme a driving speed which will be maintained constant automatically

until he or she changes it. This automatic regulation means that an average

speed is achieved by means of a progressive acceleration without peaks or

drops, which reduces the energy consumption due to the greater smoothness of

acceleration and to a more constant friction coefficient.

Furthermore, when buying a new vehicle, newly developed, cleaner and more

efficient technologies should also be taken into account, (vehicles which run on

natural gas, hybrid or electric vehicles), as well as the importance of the having

an administration which sets an example in terms of energy efficiency and

saving. The lower consumption of hybrid cars is based on the adequate combination of

an electric motor and an internal combustion engine. When the vehicle sets off,

the electric motor’s increased par is used, once the speed increases the

combustion engine takes over. When the car breaks, the energy which is

normally lost in the way of heat is used to recharge the batteries of the electric

motor.

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HYBRID VEHICLES (featuring energy label “A”)

Advantages:

Lower consumption than those vehicles which only use an internal combustion engine. The consumption can be reduced by approximately 40% with regard to another similar traditional vehicle.

Lower running costs due to its lower consumption.

Disadvantages:

Slightly higher initial price.

Additional costs:

Below we have included additional costs and the return period for the additional investment with respect to a vehicle with an internal combustion engine of similar characteristics: (values for 25,000 km/year).


Saloon 5,000 euros 6.25 years

Recommended technical specifications for a saloon type hybrid vehicle (petrol - electric)

- Electric motor + petrol motor. - Possibility to run 100% using the electric motor. - Acceleration from 0 -100 km/h: < 11 seconds. - Average sensible consumption: < 4.6 litres / 100 km. - Emissions: < 110 gr. CO2 / km. - Disc brakes on all four wheels. - Anti-lock brakes featuring electronic brake force distribution. - Emergency brake system.

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- ISOFIX anchorage for child seats with two upper anchorages. - Front and rear curtain airbags. - Front and side driver and passenger airbags. - Electric boot opening. - Side impact bars. - Remote control central locking. - Front three point seatbelts with pre-tensioner and force limiter. - Height adjustable front seatbelts. - Rear three point seatbelts. - Automatic climate control. - Speed control (Cruise Control). - Touch screen displaying average and instant consumption information,

energy flow control, outside temperature, etc. - Electric front and rear windows. - Electronic traction control. - Stability control. - Fog lights. - Electronic immobilizer. - Alloy wheels. - Illuminated boot. - Air particle microfilter. - Height adjustable front lights: manual. - Foldable rear seat. - Acoustic indicator to indicate seatbelts are not fastened. - Electric power-steering. - Regenerating brake system. - Guarantee (minimum):

- 3 years or 100,000 km vehicle guarantee. - 8 years or 160,000 km for all hybrid components. - 12 year anti-corrosion guarantee.

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The acquisition of an electric vehicle should be studied for short journeys and

for use around the city.

The main advantages of these types of vehicles is their lower energy

consumption and above all a much lower pollution level (not only in terms of

noise but also with respect to gas emissions).

There are electric vehicles available on the market which feature the following

characteristics:

Energy consumption around 0.22 kWh/km.

Engine power around 25 CV.

Tax horse power around 2 CV.

Approximate weight of 1,000 kg.

Maximum speed between 90 and 100 km/h.

Acceleration from 0 to 50 km/h in about 8 sec.

Autonomy of about 75 km.

Maximum recharge time of around 8 h.

A.2.6.2. Lorries and buses For this type of vehicles there are also considerable consumption differences

between different models and manufacturers, it is therefore necessary to keep

this in mind at the moment of purchase.

As with light vehicles, for short journeys and for use within a city, the acquisition

of electric vehicles should be studied due to the reduction in noise and

consumption that this entails.

For longer journeys, the viability of hybrid or natural gas vehicles has to be

taken into account.

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A.2.6.3. Maintenance Whether a vehicle is serviced regularly or not can have significant

repercussions on energy saving, on environmental protection, on increasing the

working lifetime of the vehicle and on increasing road safety. Similarly, it is necessary to check the tyre pressure regularly and also the wheel

alignment. It should be kept in mind that incorrect pressure or alignment can

mean an increase in fuel consumption, a reduction in the working life of the

tyres and a reduction in safety (a pressure of 0.3 bar under the level

recommended by the manufacturer can increase fuel consumption by up to

3%). It is also necessary to carry out the regular services established by the

manufacturer (the incorrect choice of oil can mean an increase in fuel

consumption of up to 3%, as well as deteriorating the engine). Monitoring a vehicle’s fuel consumption and taking note of the kilometres and

litres of fuel each time the tank is refilled, helps to detect any anomalies in the

condition of the engine.

100)/( xkminitialrefillingwhenkm

refilledLitreskm100litresnConsumptio−

=

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- Energy consumption should be an absolute priority whenever a public

administration acquires a vehicle.

- Public administrations should either purchase vehicles which include an

energy label “A”, or those which include technology that contributes to

the diversification of energy sources (electric, biofuels, G.L.P, natural

gas, ...) or to the experimental development of potentially efficient

technologies (hybrids, fuel cells, ...)

- It is recommendable that any vehicle acquired for moving around a city

or for short journeys should not have an engine power greater than 70

CV (51.45 kW). It is convenient that those light vehicles which are

needed for longer journeys, mostly for use on motorways, have a sixth

gear, so that at greater speeds (100-120 km/h) the number of

revolutions per minute, and therefore the fuel consumption, is

moderate.

- It is recommended that vehicles be purchased with instant consumption

information indicators which contribute to an energy efficient driving

style.

- Speed control mechanisms (Cruise Control) should also be included

given that they help to reduce fuel consumption during journeys at

constant speeds.

- It is recommendable to purchase vehicles which include navigation

systems, or their subsequent installation, for they contribute to the

optimization of routes and reduce the time and distance of journeys.

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B. BUILDING DESIGN The needs of modern-day life and an increase in the quality of life demand that

buildings have a growing number of facilities. Long gone are the days when the

original concept of a building was simply a place where to shelter from the

elements, where to light a fire so as to protect oneself from the harshness of

winter and to gather with others. Nevertheless, even during these times it was

obvious how important it was for buildings to maintain a certain adequate level

of temperature, humidity, light and cleanliness, so as to minimize the

consumption of firewood, which at times could be scarce. Nowadays, any

building in the services sector or used for housing still demands these same

conditions (separate a space from the outside, with easy access, acclimatized,

well lit and ventilated) with better quality; and there are additional services such

as running hot and cold water, sewage evacuation, electric energy, telephone

and data transmission connections, flexible use, ...

These improved additional facilities almost unavoidably entail an associated

increase in energy consumption. When designing a building, it should be taken

into account that the final design and the quality which is included are both going to depend on energy consumption for a long period of time, 20, 50,

100 or even more years. At this point it should be highlighted that the production of energy, even by means of well-known clean technology, brings about a strong environmental impact. The energy consumption per capita in EU countries reaches much higher levels

than the global average and these are clearly incompatible with the

unrenounceable objective of sustainable development. This is a reality, in part

motivated by a culture which encourages consumer spending and a generalized

lack of concern with regard to saving energy, all within a context where energy

products make up a relatively trivial proportion of family and business

expenditure.

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Primary energy consumption per capita Year 2004 (ept/inhabitant)

World average 1.77 Germany 4.22 Spain 3.33 France 4.43 Greece 2.76 Italy 3.17 Portugal 2.52

Source: AIE

In this kind of environment it is obvious that different public institutions have a

responsibility in so far as the energy education of citizens and companies, a

fundamental milestone of this being the example set by the administration.

This is a coherent practice which is necessary so as to demand the same from

private buildings, and furthermore, it is necessary in order to motivate and

consolidate innovation in the field of energy efficiency.

For these reasons, the exemplary energy efficient role, which the administration should play, justifies any slight additional costs that councils should accept and think nothing of it, whilst being aware that this

will mean lower operating costs and greater comfort in the facilities.

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B.1. PROJECT CONTRACT

As mentioned above, the design and construction of a building determines the energy consumption of the activity which is to be carried out in it during a long period of time, 20, 50, 100 years or more. Any energy

optimization measures which may be introduced at a later stage, once the

building has been put into operation, will be less effective and much more

expensive than if they are provided for in the technical project.

For this reason, all public administrations are obliged to take into account energy criteria beyond the minimum legal requirements, whenever conceiving and contracting a building.

Obviously, not all councils have a qualified technical team to specifically define

any particular energy efficiency requirements required from any facility.

Furthermore, even when technical personnel is available, those solutions which

they take into consideration may not be the most adequate or compatible with

the sought after application.

For this reason, we recommend to always include a clause in the specifications for technical conditions, which indicates that the projects should guarantee compliance with the maximum energy classification (2002/91/CE Directive of the European Parliament and Council, of 16th

December 2002, regarding energy performance of buildings) and the justified increase of the energy efficiency of the equipment being acquired should also be regarded as an improvement. Consequently, it will be bidders who are obliged to constantly update their

knowledge of energy saving and efficiency and they will have to keep council

technicians informed. Moreover, the knowledge acquired by companies will help

to improve private buildings.

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The specifications for administrative clauses should specify the importance of

the energy efficiency evaluation, along with any other aspects which are

considered of interest, such as price, appearance, usefulness, execution time...

we recommend that the percentage corresponding to energy efficiency should not be lower than 20% of the total maximum number of points.

We would like to highlight that because administrations are under the obligation

to provide an example, this more than justifies any possible additional costs

which demanding maximum energy efficiency may bring about.

SUMMARY SECTION B.1

- The production and consumption of energy gives rise to a strong

environmental impact.

- The design of a building influences its energy consumption during a

long period of time.

- Public administrations are obliged to set an example with regard to the

rational use of energy.

- The specifications for contracting a public building should demand the maximum energy efficiency classification. Besides, an objective points system should be included in order to prioritise those justified improvements in energy efficiency offered by bidders.

- Acting as an energy efficient role model justifies any slight surcharges.

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B.2. DESIGN PHASES The 2002/91/CE Directive of the European Parliament and Council, of 16th

December 2002, regarding energy performance of buildings sets out the

obligation to make energy classification certificates available to consumers or

users. This certificate should include objective information regarding the energy

characteristics of buildings in order to be able to assess and compare their

energy efficiency in a simple manner. For this reason, the certificate should

include reference values and comparative evaluations.

A possible way to accomplish this is by means of a classification of the building

as a whole by a certification company, establishing criteria so that anybody can

distinguish the different efficiency levels (for example, using a letter of the

alphabet, the closer to “A” would indicate the greater the efficiency level).

Consequently, the construction of highly efficient buildings is motivated as well

as investments in energy saving.

B.2.1. Building orientation

A good design, keeping in mind bioclimatic criteria can obtain savings of up to

70% in the acclimatization and illumination of a dwelling. All of which implies an

increase in the construction costs no greater than 15% above the standard cost.

Bioclimatic design does not refer to any type of special architecture, but rather

to any architecture style which takes into account the location of the building

and the microclimate which surrounds it, in order to adapt the construction to

the setting where it will be raised. The efficient design of a building or of a

detached house will manage to exploit free energy to the utmost, avoiding

undesirable losses/increases in heat and optimizing the efficient running of

equipment.

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It is necessary to consider new facilities as a whole, integrating the design of

the envelope (typology) with other factors, such as the selection of materials,

natural illumination and other passive solar energy tappings, heating, ventilation

and air-conditioning systems, illumination systems and remaining equipment.

An important factor to take into account is the climate, due to the fact that these

conditions should give rise to different strategies. Similarly, it is convenient to

make the most of favourable weather conditions; these are very closely linked

to the location and orientation of the building, therefore:

A badly oriented building or one with an inappropriate shape can need

more than double the energy of a similar well designed construction with

a good orientation.

Another objective should be to try to reduce the negative effects of the

wind and the cold which are most dominant in the chosen location.

The design should try to maximize the use of solar energy by means of

the structural elements of the construction itself (passive solar energy) or

by means of the use of specific equipment capable of transforming useful

solar energy into energy.

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Trees, hedges, bushes and climbing plants, when located in appropriate

places, not only improve the appearance and the environmental quality, but

they also provide shade and protection against the wind. Similarly, the water which evaporates during the photosynthesis process cools the air and can bring

about a slight drop in the temperature, between 3 and 6 ºC, in those areas

which have trees. Furthermore, trees with deciduous leaves provide an

excellent degree of protection against the sun in summer and allow the sun to

warm the house in winter. Moreover, if we surround the building with vegetation

(grass, plants, etc.) instead of cement paving, asphalt or similar materials, we

can achieve a reduction in the accumulation of heat.

With an appropriate positioning, any windows and glazed doors, greenhouses,

cloisters and courtyards can allow the solar radiation to penetrate directly into

the spaces which are to be heated in winter, consequently saving energy in

terms of heating.

In cold areas, it would be interesting to position the largest surrounding walls

facing South as well as any glazed surfaces in the most frequently used rooms,

and those facing North should be as small as possible.

In warm areas, on the other hand, it would be more convenient if those

positions with the most solar radiation (South and Southwest) had the least

glazed surface possible.

Shape plays an essential role in the heat losses of building. In general terms,

we can state that compact structures which include rounded shapes have fewer

losses than those structures which features several openings, hollows and

projections.

Another fundamental factor in the design is the activity which is going to be

carried out inside the construction, and together with the climate, these will

determine the acclimatization needs.

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On the one hand, we can find the activity level of the occupants and the

emissions from equipment and machines, on the other we have the exterior

environment. The relationship between both thermal loads affects the degree to

which the building losses or gains heat.

The following list can be used to verify the conditions during the design phase of

the building.

Climate

Consider the specific climate conditions in the area.

Consider the specific exposure to the sun (characteristics of shade) in the area.

Orientation and shape

An appropriate orientation should be chosen, as far as possible.

Arrange exterior and landscaping elements so that they can actively form part

of the energy saving control.

As far as possible, chose the most “compact” solution, within those that fulfil all

the requirements that the building will need to meet.

Openings

The size of these openings, their proportions and position in the façade will

comply strictly with the building’s requirements in terms of natural light, heating

and ventilation.

Reject single glazing windows, instead of double glazing (single air space) or

triple glazing (double air space), and always including thermal break frames.

Wherever possible incorporate integrated shading systems into the façade.

The fixed variety (which are longer lasting, but not so effective) or

folding/adjustable (more prone to deterioration, but they can be adapted to the

different seasonal conditions).

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Thermal efficiency

Determine the purpose of the building and the amount of equipment which will

be installed, their power and operating hours, because these will determine the

internal thermal load.

Pay special attention to façades, openings, roofs and floors, making sure that

they include the appropriate thermal resistance in order to maintain the comfort

and efficiency conditions.

Condensation prevention, to this respect, is avoiding and eliminating any type

of thermal bridges. Continuous humidity in any element contributes

considerably to its deterioration.

SUMMARY SECTION B.2.1 - If the administration issuing the tender can obtain the most

representative climate information for the future construction site,

these should be included in the contract specifications.

- On the other hand, the building project should demand a short but

detailed report dealing with the climate conditions of the site:

temperatures, humidity, exposure to the sun and predominant

direction of the wind.

- Based on these conditions, the project should justify the

orientation of the building and the location of each of the rooms

inside it. If the orientation is imposed by the site, this would justify

adapting the building envelope to meet the conditions set out by

the area and by the activities to be carried out in the building.

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B.2.2. The thermal envelope

The thermal envelope is made up of all those structural materials and finishings

which close the building, separating the internal areas (which are also fitted out

to some degree) and external areas. This definition includes the façades, openings (doors and windows), roofs and floors.

The envelope should fulfil the ventilation and natural illumination requirements,

and at the same time provide some type of appropriate protection against any

atmospheric agents. In the following table we have described some estimates of

the cost representativeness percentage for each element in the envelope with

regard to the total building cost, depending on the type of building:

Type of building Floor Façade Roof Total

Hospital with 4 – 8 floors

0.6 9.5 0.6 10.7

Production plant 6.4 9.5 6.7 21.6 Office building with

12 – 20 floors 0.3 19.9 0.4 20.6

Sports centre with 2 – 3 floors

2.3 14.5 2.5 19.3

Source: Whole Building Design Guide

Moreover, it is the element which determines the building’s exterior esthetic

quality, an important aspect when designing installations for public services

such as municipal buildings. By working on the envelope or skin of the building,

energy resources in the immediate vicinity can be harnessed, retained and

stored. Furthermore, the way in which the different openings are arranged and

the distribution of the different rooms can favour natural ventilation.

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One way of avoiding temperature increases in summer is the use of evaporating

systems and water cooling systems. Therefore, placing a curtain or water sheet

on a wall will increase the comfort sensation in summer. The heat is absorbed

by the water as it evaporates and the wall is kept at a lower temperature,

resulting in a cooling effect inside the dwelling.

The basic function of the elements of the envelope is the separation of different

environments, supporting all types of loads (structural and thermal) and also

fulfilling an esthetic function. It is worth detailing the following elements:

• Façade: vertical exterior enclosure.

• Party wall: vertical enclosure in contact with another building or adjacent

site.

• Roof: superior enclosure.

• Lower wall: inferior vertical enclosure in contact with the ground.

• Partition: interior vertical enclosure between the spaces of a building.

• Mortar / Flooring: horizontal enclosure between the floors of a building.

Other elements which are present in the enclosures are openings. The

fundamental types of openings are included in the following list:

• Window: vertical glazed opening.

• Skylight: opening located in the roof.

• Door: opening which allows the passage of people and objects.

B.2.2.1. Façades These are the vertical enclosures which separate the interior environment of the

building (generally they are fitted out in some way), from the exterior space. The

elements which make up this part of the building are the following:

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a) Exterior finish The natural or synthetic elements which constitute the more exterior layer of the

façade. They are the first barrier of protection against external agents, also

acting as protection for the elements on which they are fixed. They determine

the final visual appearance of the building. The characteristics of those

elements which are related to the nighttime reflection of solar radiation and to the emission of infrared radiation should be taken into account with

respect to the exterior finish.

Dark colours for finishes favour the effects of the absorption of solar radiation,

increasing the heat in winter in cold climates, an effect which in summer can be

compensated by means of the incorporation of shading elements or ventilated

air chambers. In the case of solar protection, it is recommended that South facing areas be fitted with fixed or semi-fixed protection, whereas for

eastward or westward facing spaces the most adequate is movable protection which allows sunlight to enter during colder spells. In the following

table we have detailed a series of solar protections and the estimated

percentage of energy saving in cooling:

SOLAR PROTECTION % Dark colour curtain 42

Medium colour curtain 53

Light colour curtain 60

Dark colour blind 25

Medium colour blind 27

Light colour blind 40

Dark glass (5 mm) 40

Polarized glass 48

Heat absorbing blind and glass 47

White blind 85

Cloth awning 85

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In warm climates, on the other hand, it is more interesting to include a finish in a lighter colour which maximizes the reflection of radiation, maintaining the

rooms fresh in summer periods when temperatures are high.

On the other hand, at night exterior surfaces are cooled due to the emission

of infrared radiation towards the sky.

Whitewashed finishes, which are typical in Mediterranean climates, feature a

high level of solar radiation reflection and a high level of infrared radiation

emission, therefore this typical architecture of these areas uses these effects to

maintain a comfortable temperature inside the dwellings.

b) Insulating element These are materials which are characterized by their increased thermal resistance, that is to say, low heat conductivity.

As mentioned above, air can be used as an insulator, but the convection

phenomena which take place in air chambers make it more adequate to use porous or fibrous materials; these are able to immobilize the air and confine it

to the inside of small cells, which are more or less air-tight.

The variations in the design are the thickness of the material, its thermal

conductivity and its density. If the design were to include only one type of

constituting element for the enclosures, the need to fulfil minimum insulating

standards would call for a considerably thick width.

The most commonly used elements are polystyrene, polyurethane,

fibreglass and Rockwool, a more detailed description of which is provided

below.

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Fibreglass.- This is a fibrous material which is obtained by making molten glass

flow through a series of very small holes. When it solidifies, it has enough

consistency and the flexibility to be used as fibre.

It has the advantage of being resistent to humidity,

but it is absorbent, and when it becomes wet it

loses its insulating ability.

On the other hand, the use of fibreglass as

insulation brings about a series of health problems

during its installation:

In direct contact, it can irritate the skin, eyes, nose and throat.

Being exposed to high levels of fibreglass in the air can aggravate asthma

or bronchitis.

Once it has been installed, there is no risk of direct contact, except if the elements

were to deteriorate.

Characteristics Typical values Thermal conductivity (λ) 0.041 W/m ºK

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Rockwool.- Rockwool is a material made using

basaltic rock. It is sold in the shape of plain or

covered panels, felts, reinforced blankets, fluff...

It has the disadvantage of losing its properties when it

becomes wet.

The production process tries to reproduce the natural process in a volcano.

The rock melts at temperatures over 1600 ºC. This liquid rock is transformed into

fibres by means of a centrifuge process. Straightaway, and by using

agglomerates, a substance is formed which is then used to manufacture the

different products.

Characteristics Typical values Density 175 kg/m3

Thermal conductivity λ 0.03 – 0.04 W/m ºK Water absorption 79% vol.

Polystyrenes.- Polystyrene is a polymer of styrene, produced by means of the dehydration

of ethylene, which in turn is produced during the vaporization of the naphtha from the

crude distillation process.

An expanding agent is used in the polymerization of styrene, provoking a formation known

as “pearls” with diameters between 0.4 and 2 mm.

Starting with this pearl and depending on the posterior process, we can find expanded

polystyrene (EPS) or extruded polystyrene (EXP), both of which have their own particular

characteristics.

Characteristics Units EPS EXP Density kg/m3 13 – 15 33 Thermal

conductivity (λ) W/m ºK 0.040 0.033

Water absorption % vol. 2 – 5 <0.5 In places where the filtration of water is likely (due to an increased pluviosity), this type of

material would be preferable as opposed to others such as Rockwool.

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Polyurethanes.- The most important physical properties are density, thermal and

hygrothermal behaviour.

In so far as its density, the most usual value ranges between 30 and 60 kg/m3. It

has a thermal conductivity coefficient which varies between 0.012 and 0.020 W/m

ºC. Water absorption reaches values which vary between 2% and 5%.

Polyurethane deteriorates when exposed to high temperatures (it should be

protected or painted when installed), as well as when in contact with water,

therefore it would be more appropriate for use in temperate climates with low to

medium rainfall.

Characteristics according to density Density (kg/m3) � (W/m ºK)

9 – 10 0.047 11 – 12 0.045 13 – 15 0.040 18 – 20 0.037 22 – 25 0.035

c) Air flow and water vapour control elements This is a series of elements in charge of controlling and limiting the flow of air

and/or water vapour through the enclosure.

Whenever there is an considerable flow of humid air from the interior of the

building, a large amount of water vapour reaches the exterior surface of the

insulation, thus producing condensation on the inside of the enclosure, which

would bring about a deterioration of the insulating element if it were to take

place continuously.

The installation of the barrier should be carried out on the warm side of the enclosure, because this will make its behaviour more effective.

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Some thermal insulating elements also work well in this sense (besides their

real purpose, which is preventing the flow of heat), and the amount of vapour

which would reach the cold side of the insulation is very small.

A vapour barrier is absolutely essential in very cold climates, when the

insulation is installed on the inside of the enclosure and the resistance to vapour

on the exterior surfaces is high.

Finishes using materials such as natural stone behave well in this sense and they act as vapour barriers on the cold face of the enclosure.

d) Structural elements These can be concrete enclosures manufactured on site, prefabricated

enclosures (made of wood, concrete or even plastic), or masonry, made up of

resistant materials (stones, ceramic bricks or prefabricated concrete blocks) put

together by means of a mortar, consisting of cement, water and fine arids

(sand). For better thermal insulation, it is recommendable to construct two masonry walls with an air chamber and some type of projected insulating element between them.

e) Interior linings This does not have any important consequences from a thermal efficiency point

of view, but it does influence the building’s total energy consumption.

An important design variable is the level of natural and artificial light reflection. The objective in these cases is to obtain an appropriate visual

comfort level with a minimum energy consumption; this subject is dealt with in

more detail in the artificial lighting section.

In the case of floors, if direct solar radiation can reach their surface, they can

contribute to the warming of rooms. Nevertheless, it is advisable to use

materials which are able to reflect sunlight in a controlled manner (so as to

avoid any glare), and thus reflect the radiation onto interior walls, so that these

are the elements responsible for the absorption and accumulation of heat.

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B.2.2.2. Other types of façades

Curtain walling These are stackable and light enclosures, made up of several layers

(waterproof exterior, insulating interior and an absorbing interior finish). They

are fixed to the main structure and can be arranged either vertically or

horizontally.

Furthermore, they are fireproof.

They are not expensive and can be installed in short periods of time, and they

can also feature the possibility to incorporate solar energy harnessing

elements (panels).

They also offer the possibility to modify the solar energy harnessing level (passive exploitation) by means of the use of special glasses, but this would require the installation of thermal insulation.

Even though subject to variations, the glass covered sections of curtain walling

represent 55% of the total surface, the opaque elements cover 35%, whilst the

remaining 10% correspond to the metal structure.

Their main use is as the external façade for outstanding buildings which have

a highly representative character.

In general, their energy performance is quite deficient, therefore it is

recommendable to minimize their use.

Sandwich panelling These are made up of elements which consist of several layers, each of which

has a different purpose. It is worth highlighting some of their characteristics:

High mechanical resistance and extremely light.

Low thermal transmission coefficient, therefore they do not need additional layers of thermal insulation.

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Resistant to corrosion and deformation.

They are fireproof.

Their appearance is appropriate without any type of covering.

They are not expensive and can be installed in short periods of time.

Their main use is as the exterior façade of industrial buildings, warehouses,

sports centres...

B.2.2.3. Openings These are openings made in the enclosure and their purpose is to provide light

and ventilation to the corresponding rooms, as well as access to the same.

Openings are the parts of the envelope which are the most susceptible to

having a lower thermal insulation with respect to the exterior environment. For

this reason, under no circumstances will an efficient building ever make use of

solutions based on single glazing; the most adequate option is double glazing

for temperate climates and triple glazing for those areas where winters are

particularly harsh.

Whenever there is a considerable difference between the exterior temperature

and the temperature inside the building, not only in summer but also in winter, it

is necessary to install additional thermal protection elements such as shutters or

airtight blinds during winter periods, and elements to control the insolation

during summer periods.

In any case, a possible design option is to reduce the glazed surface, in order to

moderate any likely heat flow.

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Double glazing.- This is the perfect solution for moderate climate.

They are generally manufactured with PVC or aluminium to make the frames,

anodized in a variety of colours. Wooden window frames can increase the

insulation, but this would mean an increase in price.

Wood framing is used in the restoration of buildings which have a certain

traditional character or in order to comply with municipal bylaws.

Triple glazing.- This is the appropriate solution for the most severe climates.

Moreover, they also provide the best conditions in terms of soundproofing,

even though they are expensive solutions.

Double window.- In the case of restoration works the most common situation

is to find solutions based on single glazing. Even though one option would be

to replace these elements for more efficient ones, it may be interesting from an

economic point of view to install a second window with the same

characteristics besides the original, as long as the original window is in a good

condition, leaving an air chamber between the two.

Consequently, improvements of up to 65% can be obtained as opposed to the

original solutions based on single glazing windows.

In any case, it would be necessary for either the user or the building designer to

carry out a brief viability study for the installation of these different options.

In the following table, as a reference guide, we have detailed the thermal

transference coefficients K for the different types of glazing and for different

frame materials. The lower the value of K, the more efficient the thermal

behaviour. The thickness of the glass can range between 4 to 10 mm.

Dehydrated gas is introduced inside the air chamber or chambers (in order to

prevent interior condensations) or a high density gas (argon or krypton).

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Type of glazing

Thickness of the air

chamber (mm) Kglass

Type of frame material

K (glass + framing)

Kcal/m2 hºC

Single -- 4.9 Wood 4.3

Metal 5.0

Double

6 2.9 Wood 2.8

Metal 3.4

8 2.7 Wood 2.7

Metal 3.3

12 2.6 Wood 2.5

Metal 3.2

Triple

6 2.1 Wood 2.4

Metal 2.9

8 1.9 Wood 2.3

Metal 2.8

12 1.8 Wood 2.2

Metal 2.7

Source: ISOVER Manual: Building insulation.

B.2.2.4. Roofs These are elements which are watertight and resistant to precipitation, limiting

the uppermost part of the building. They are classified keeping in mind different

criteria:

According to inclination

• Flat roofs.

• Sloping roofs.

• Single-face roofs.

According to structure

• Roofs with a reticular structure.

• Roofs with a laminated structure.

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According to the installation order of the roof layers

• Traditional roofs.

• Inverted roofs.

According to the hygrothermal behaviour

• Cold roofs.

• Warm roofs.

These classification criteria are not excluding.

Below, we have included a slightly more detailed description of the

classifications in terms of energy related aspects, such as the variety based on

the installation order of the layers or on the hygrothermal behaviour.

Types of roofing according to the installation order of its layers

Traditional roofs. These are characterized by installing the waterproof layer

first (most exterior) and the insulation layer next (most interior).

The disadvantage of this system is that under the insulation a vapour barrier must be installed so as to prevent any condensation being formed under the

waterproof layer or at any point inside the insulation.

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Inverted roofs. These consist of the alteration of the order of the layers of a

traditional roof.

In these roofs the waterproof layer is placed just under the thermal insulation

and also acts as a vapour barrier.

Among the advantages of this system are its improved durability, insulation,

comfort and resistance to condensation; its easy installation and maintenance

and lower maintenance costs.

1. Mortar 2. Sloping concrete 3. Adhesive – vapour barrier 4. Thermal insulation 5. Waterproofing 6. Mortar layer of 3 - 4 cm 7. Bonding mortar of 2 cm or cement glue 8. Ceramic tile finish

Roof types according to hygrothermal behaviour

Cold roofs. This type of roof are made up of two elements, separated by an air

chamber in contact with

the exterior environment,

under the covering

material.

They are neither air- nor

water vapour-proof, which

dissipates through the

covering material.

Organizational layout of the roof:

Upper layer: Covering material which will have to be waterproof.

Intermediate chamber: Made up of a space which is ventilated by air from the

outside.

Element A

Element B

Cold Air chamber

Warm Interior

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Lower layer: This provides any necessary thermal insulation for the heat which

is inside the building not to dissipate.

Warm roofs. These are made up of only one element which separates the

interior and exterior, without an intermediate air chamber.

It should be kept in mind that in solutions of this type many of the materials

which are used in the construction are permeable to water vapour to a greater

or lesser degree, consequently vapour diffusion will take place on the interior

face of the roof from the warm environment towards the cold side, and this

could bring about condensation in the interior of the mass, thus making it

necessary to install a vapour barrier. The roof itself is made up of various

layers of different material, each of these fulfilling a specific purpose.

1. Covering material.

2. Waterproofing.

3. Thermal insulation.

4. Vapour barriers.

5. Slope forming material.

6. Mortar.

Cold roofs have traditionally been installed in warm climates.

These roofs are useful in summer because the air chamber compensated the

effect of strong solar radiation on the surface of the roof. In winter the constant

renovation of the air inside the chamber cooled the space it protected and so

keeping the heat inside proved expensive.

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Nowadays, the insulation which is available has provided a solution to this

question and a ventilated roof can be used in any location. Nevertheless, it is not recommendable to use ventilated roofs (cold) in climates which are not that warm, and warm roofs should be used instead.

Among flat roofs, the most common are the warm variety, due to the fact

that they manage thermal flows more efficiently and they are easier to install.

The elements which make up a roof are those we have detailed below:

a) Exterior finish

Among the most commonly used elements, we can find the following:

• A wide variety of different tiles (ceramic, which are the most common type used in civil constructions, concrete or even plastic).

• Slate plates.

• Sandwich panels.

• Corrugated metal sheeting.

• Anodized aluminium sheeting.

These last three are basically used in buildings of a certain singularity, industrial

warehouses and/or sports pavilions. Their most noteworthy characteristics are

those which we have detailed below.

Ceramic tiles.- Increased durability. Low thermal conductivity and appropriate

acoustic insulation. They are fire-resistant. Up to a certain point, they can be

installed wherever esthetic requirements are strict. They are used above all for

sloping roofs of detached houses.

Slate.- Increased durability. Low thermal conductivity, but higher than that of

ceramic tiles. They feature an appropriate level of acoustic insulation. They are

fire-resistant. The minimum recommended slope of the roof for their use is 18º.

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Method used for the ridges or folds in the roof: slate sheets or zinc sheets

(more appropriate). They can be installed on sloping roofs for detached

houses.

Sandwich panels.- They are extremely light. They are not expensive and can

be installed in short periods of time. They feature the capacity for thermal

insulation without additional elements and for solar radiation reflection. They

are not good acoustic insulators. They are fire-resistant. Used in industrial

buildings, warehouses, sports pavilions..., not only for flat roofs (nonwalking)

but also sloping roofs.

Corrugated metal sheeting.- They are light. They are not expensive and can

be installed in short periods of time. They feature neither thermal nor acoustic

insulation. They can be used up to a certain point in industrial buildings,

warehouses... (whenever there are no special insulation needs). They can be

used not only for flat roofs (nonwalking) but also sloping roofs.

Anodized aluminium sheeting.- They are light. They are not excessively

expensive, but they are more expensive than the two previously mentioned

elements. They feature good thermal insulation characteristics and an

appropriate ability to reflect solar radiation. For specific applications they may

need elements which provide them with a greater level of acoustic insulation.

They can be used in apartment blocks, industrial constructions, office buildings

and detached buildings. They are used on sloping roofs.

Other elements which are present in roof ridges and joints whenever they are

flat, are the following:

• Paving stones or tiles (for pedestrian use).

• Asphalts (for motorized vehicles).

• Vegetation elements.

• Gravels.

The last two are used on nonwalking flat roofs, even though they may be

accessible for maintenance purposes.

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b) Waterproofing and thermal insulating elements

As mentioned above, in the section dealing with roof definitions, it is possible to

install the waterproofing element over or under the insulation, giving rise to the

two aforementioned typologies: traditional roofs and inverted roofs.

The insulating materials which are used are the same as those included in the

section dealing with façades and their characteristics can be consulted in that

section.

c) Structural elements These can be prefabricated concrete elements (beams), elements made of

metal (porches for sports centres, in warehouses for exhibitions, etc.) or wood,

even though this last solution is fundamentally used in residential constructions,

and is installed in exceptional cases in municipal buildings.

B.2.2.5. Horizontal divisions Within this section we have included all those horizontal separation elements

between the (flat) spaces of a building.

In those cases where the floor of the dwelling is in contact with the ground, it

will be necessary to incorporate some type of insulating element to be installed not only horizontally but also vertically, in those cases where the

lower wall is located underneath the level of the ground.

Lower wall placed on the ground.

Horizontal insulation strip. Lower wall placed on the ground.

Vertical insulation strip.

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In those cases where the presence of water is likely, the installation of

waterproofing elements and drainage layers to avoid water stagnation is

recommended. Other typologies besides ground level flooring and semi-buried

walls are walls which are completely underground, underground mortar work

and roof gardens.

In the case of underground mortar work, these are more common in garages

and basements, which are definitely not inhabitable spaces, therefore they will

need any corresponding waterproofing layers, but not insulation.

It would be necessary to insulate the basement in those cases in which it is

occupied or if some type of activity is to be carried out which would require a

certain level of comfort.

The insulation level should include similar characteristics to that used in the

case of roofs, taking into account that we are definitely dealing with upper

enclosures in contact with the exterior or with non inhabitable spaces.

A similar consideration can be applied to the case of roof gardens, even though

in this case, we have before us the incorporation of a control element of the

thermal flow such as the vegetation layer.

These varieties of roofs were traditionally used as insulation in cold climates,

but they offer important opportunities in terms of refrigeration during summer

periods, due to the transpiration mechanism of the plants and the watering

control.

Notwithstanding, the advantages of this type of solution as opposed to an

appropriate insulation have not been totally demonstrated. In the case of

masonry work between floors, that is to say, separating the (outfitted) levels of a

construction, the level of insulation provided by the mortar itself is usually

enough, along with the suspended ceiling and the horizontal air chamber that is

formed between them, without the need to install additional insulating elements,

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unless any part of the mortar work is in contact with non inhabitable spaces or

directly in contact with the exterior environment, in which case it would be

necessary to install corresponding layers of waterproofing and insulation.

It is also important to remember that the time needed to warm a room will also

depend on the height of the ceilings, therefore as a general rule, the most

compact options should be the most common, that is to say, options where the

ceilings are as low as possible.

B.2.2.6. Interior partitions These are walls which separate the different rooms within the same building, or

which separate inhabitable (outfitted) spaces from uninhabitable areas (in

contact with the exterior and therefore not outfitted), also within the same

construction.

In the first case, given that the comfort levels inside the different spaces of a

dwelling are similar, this type of partition should fulfil a merely acoustic

insulation purpose. The most common constructive solutions are those which

are based on hollow bricks, either single or double, or those based on

plasterboard sheets.

In the case of enclosures in contact with non inhabitable spaces, the

characteristics of the insulation should be the same as those for façades and therefore it would be necessary for them to include insulating elements

which guarantee the interior comfort conditions.

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SUMMARY OF SECTION B.2.2 - The envelope of a building should guarantee the correct thermal

insulation from the exterior of the entire perimeter, therefore it is

necessary to justify the need for openings and the ideal positioning of

these, demanding solutions which feature appropriate thermal

characteristics.

- At the same time, the envelope should make the most of the natural

light available, in accordance with the purpose of the building.

- The envelope should favour the harnessing of the positive effects of

solar radiation and other environmental characteristics, limiting their

negative effects.

- The rational use of natural elements should be promoted, such as

plants, water and also colours, so as to condition the environment and

minimize energy consumption.

- Priority should be given to the use of construction materials which require little energy during their manufacture, use or demolition,

not only for the envelope but also for the rest of the building. - Similarly, an adequate thermal behaviour will have to be guaranteed for

those interior divisions between spaces with different environmental

demands or with different occupation times.

- The technical project of the construction of a building should not only include the solution to be adopted, but also the justification of the same.

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B.2.3. Heating and hot water equipment

(For more information regarding central heating installations, please turn to section A.2.5.2.1) Central heating necessities depend on specific factors such as climate,

orientation, the quality of those construction materials used, the insulation and

what the rooms to be heated are used for. The first step when preparing the

central heating and/or hot water for sanitation project is to calculate

requirements. Logically, in order to guarantee comfort, the final dimensioning of

the system will be made considering the most adverse circumstances, in other

words, a maximum internal demand and the worst environmental conditions.

Notwithstanding, the system’s operation at partial loads should be predicted, as this will be the most commonly used, in order to ensure an optimum performance of the equipment in these conditions. In certain

circumstances, this may mean that equipment should be duplicated if it does

not function at an optimum performance under partial load conditions; for

normal conditions it would be enough to run just one, but whenever the demand

is very high both units would have to be put into operation. This doubling of

efforts would also increase the reliability of the system, given that any possible

failure of either of the devices would not prevent the operation of the other.

The most important parameters in so far as determining a comfort situation, are

the following:

- temperature,

- the quality of the air,

- relative humidity. Taking into account the optimum temperatures of rooms, this would depend on

their use. As a guideline, we have described some approximate temperatures

for different work areas in a municipal building.

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ROOM TEMPERATURE (ºC)

Reception 18

Administration 20

Secretary’s Office 20

Classrooms 18-20

Library 21

Offices 20

Assembly hall 20

Meeting rooms 20

On the other hand, the quality of the air depends of several factors and mainly

on using exterior air for its renovation, which should not be lower than 30 m3/h

per person.

In so far as relative humidity, this should be fixed between 30 and 70%.

Once these standard parameters have been defined for all of the rooms in the

building, the appropriate control equipment should be available at the project

and construction phases so as to guarantee these levels of comfort.

B.2.3.1. Central heating systems

Heat generation.

Once the central heating needs have been defined, and before choosing the

most adequate central heating system, the following questions should be

answered:

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1.- Is there any harnessable residual thermal energy available? Some of

the planned machines or processes within the building itself can generate

considerable quantities of thermal energy when being refrigerated, and this can

be harnessed for use as heating; for example, the condensers of refrigeration

systems (the paradox may arise whereby both heat and cold are demanded at

the same time in the same building, all the more likely the larger the building

and the worse the design of the building’s positioning and its envelope).

Outside the building, if it is close to some type of industrial facility, an

incineration plant for example, or an electric energy cogeneration plant,... it is

very likely for it to have a surplus of low temperature thermal energy (difficult to

assess for the industrial process itself) and can even be consuming electric

energy in order to dissipate it (air flasks, evaporation condensers, cooling

towers,...). In these cases, above all if the building being planned has a rather

high consumption, the viability of harnessing residual energy should be

considered.

2.- Is there any type of centralized heating system near the building? As

explained in more detail in section B.3.2, the performance of centralized

systems can be greater and they make it easier to harness energy sources

such as biomass, whilst minimizing any handling risks. Therefore it is

recommendable to support centralized systems in areas of increased

consumption.

Once these previous conditions have been evaluated, if an individual installation

is really necessary, either as support or as the main installation, any of the

following alternatives are recommended:

- High efficiency boiler.

- Geothermal heat pump (ground-water or ground-air)

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If any of these systems are not suitable for any justifiable reasons, the

recommended system for moderate climates should be a conventional heat

pump (air-air). Except as a last resort, in reduced consumption applications

which are far-removed from heat distribution networks, electric heating systems

can be considered as central heating options.

High efficiency boilers.

Below we have included a summary of some basic definitions with reference to

boilers:

Boiler: the ensemble made up of a body and a burner, used to transmit heat to

water by means of combustion.

Standard boiler: a boiler that features an average operating temperature that

can be limited depending on its design.

Low temperature boiler: a boiler that can work continuously with a water supply

temperature between 35 and 40 °C and which may produce condensation in

specific circumstances from the water vapour which is present in the combustion

gases without significantly damaging the boiler.

Condensing boiler: a boiler designed to be able to permanently condense a

significant proportion of the water vapour which is present in the combustion

gases.

Useful nominal output of a boiler: the maximum calorific power that the boiler

can deliver, according to the manufacturer’s guarantee, when operating

continuously, adjusted to the useful performances declared by the manufacturer

himself.

Useful performance of a boiler: the relationship between the heat flow

transferred to the carrying fluid and the result of the inferior calorific power (ICP)

at a constant fuel pressure by the consumption during a unit of time.

Calorific power (of a fuel): the quantity of heat produced by the combustion of a

fuel, at a constant pressure equal to 101,325 Pa.

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- Superior calorific power (SCP): the water produced by combustion is

supposedly condensed.

- Inferior calorific power (ICP): the water produced by combustion

supposedly remains as a vapour.

Conventional or standard boilers, under normal working conditions, require the

water outflow temperature to be maintained between 80-90 ºC and a return flow

above 55 ºC. As a result, the appearance of highly corrosive condensations is

avoided inside the combustion fumes flu expulsion tubing.

Low temperature boilers base their technology on tubing which has air

chambers capable of producing heat transmission in a measured manner, thus

avoiding the production of condensations and allowing a fume expulsion

temperature of around 130 ºC. This fume expulsion temperature, with regard to

condensing boilers, can reach up to 10 ºC above that of the return flow, with

the resulting reduction in losses.

An example of the tubing used for a condensing boiler

With low temperature and condensing boilers, the operating temperature

can be adjusted depending on the real demand of the facility, and as a result

there is no constant demand for water and an increased temperature.

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Therefore, losses because of convection and radiation are reduced and with an

adequate insulation of the boiler walls and door, these can drop further until

around 0.3%.

The performances of these types of boilers are considerably different, due to

their different technology.

In terms of condensing boilers, apart from the heat that can be provided by the

fuel, the heat from the water vapour produced during combustion can also be

recovered, thereby obtaining an energy performance slightly above 100%,

referring to the I.C.P of the fuel.

Therefore, whenever possible it is always recommendable to install either a condensing or a low temperature boiler rather than a conventional one.

Figure: Comparison of the seasonal performance of boilers

86

92

103

75

80

85

90

95

100

105

%

Convencionais Baixa temperatura Condensación

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Heat pumps.

Heat flows spontaneously from high temperatures to low temperatures. A heat

pump features technology which is capable of forcing the flow of heat in the

opposite direction, using a relatively small amount of electric energy. Heat

pumps can transfer this heat from natural sources in the environment at low

temperatures (heat source), such as air, water or from the ground itself, toward

interior rooms which need to be heated. Furthermore, there are reversible

devices which enable interior rooms to be cooled during warmer periods by

displacing the heat toward the outside.

Heat pumps are an energy efficient alternative to those systems which are

made up of a boiler and cooler, on account of the fact that their performance is

better than that of a fuel powered boiler.

Consequently, whilst the Coefficient of performance (COP), of a heat pump

ranges between 2.5 and 4.5, the average performance of a high efficiency boiler

is approximately 0.9.

To a great degree, the efficiency of this type of equipment depends on the

temperatures of the environment from where the heat is taken and the

environment into which the heat is transferred. Therefore, the greater the temperature difference the lower the efficiency of the equipment. As a result, above all in cold climates, it is recommendable to install geothermal

heat pumps, that is to say, using the ground as a heat source. When it is cold it

is necessary to heat a room to a temperature which is higher than that of the air

in the exterior environment, and this means that a geothermal heat pump can

obtain higher and more constant outputs.

Moreover, ice formation problems are avoided on the exterior unit (evaporator)

of the heat pump, which reduces the performance of equipment with an air heat

source.

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As an example, consider an air – water heat pump, with a calorific power of 290

kW. If this equipment operates at 50 ºC outflow temperature, the calorific power

which is produced with respect to the exterior temperatures, can be the

following:

Exterior air temperature

Heat production (kWh)

10 ºC 290 5 ºC 256 0 ºC 227

- 5 ºC 186

As the table shows, the calorific power of the air – water heat pump diminishes

at the same time as the exterior air temperature decreases (it is more difficult to

increase the heat); this happens during periods of higher thermal demand in the

building (when the weather is colder).

Due to the low exterior temperature and to the relative humidity, water vapour

condenses on the outside of the evaporation battery module, thus forming ice

whenever the exterior air temperature is below 0 ºC, which requires additional

energy in order to melt this ice.

In general, the performance of the air – water heat pump diminishes

considerably when the temperature of the exterior air is below 5 ºC, therefore it

is convenient to pay special attention to the equipment specifications under

these conditions.

In any case, it is preferable to install ground – water heat pumps, with more

stable performances and calorific power, and in fact the ideal moment to install

these is during the construction of the building.

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Heat transmission.

The distribution network is the installation which connects the generation of

thermal energy to the heat exchanger units. It is usually made up of a network

of hot water conduction pipes and depending on the emission system, this

water flows at a specific temperature or another.

All of the hot water piping should be conveniently insulated along the entire

length of the pipes, including any valves, connectors, clamps, joints and

equipment..., so as to avoid any heat loss from them.

The characteristics of the insulating materials, as well as the thickness of these,

will mainly depend on the temperature of the water and on the diameter of the

tubing.

A) Heat emission. The heat exchanger units are responsible for transferring the generated thermal

energy into the environment which needs to be heated.

There are several different types:

- Radiators

- Fan-coils

- Convectors

- Air flasks

- Acclimatizers

- Radiant flooring

- Radiant ceilings

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When studying the energy saving possibilities, not only should the thermal

generation systems be taken into account (boilers, heat pumps,...), but attention

should also be paid to the equipment used to distribute the heat throughout the

various rooms.

The most common systems are those which use hot water as the carrying fluid,

therefore any study should concentrate on this type of system.

Depending on the type of heat emission system being used, the thermal energy

needs will be different, due to the fact that the heat carrying fluid works at a

different temperature. Below we have included the range of working

temperatures for this equipment:

Type of unit Temperature (ºC)

Radiators 90-50 ºC

Fan – coils 55-50 ºC

Convectors 80-50 ºC

Air flasks 90-60 ºC

Acclimatizers 90-50 ºC

Radiant flooring 45-40 ºC

n general, it is convenient to apply heat at the lowest temperatures possible,

because this will increase the energy performance and comfort, nevertheless

this requires greater heat exchange surfaces and therefore more expensive

heat exchanger units.

Below we have detailed the most common types of heat exchanger units,

paying special attention to radiators, given that they are the most popular:

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Radiators. Radiators are final heat exchanger units which transfer heat into the

environment. The hot water produced by the central system is carried to the

radiators at a temperature of about 50-90 ºC. The water transfers heat to the air

– environment using the radiator’s plates by means of radiation (approximately

20%) and by convection (around 80%). The temperature of the water return flow

to the boiler is between 15 – 20 ºC due to the heat transferred into the

environment. This equipment allows the central heating

installation to be divided into zones by means of

different circuits (depending on the orientation of the

building, working hours and occupation

percentages) and they make it easy to install temperature control measures in each room (by

means of thermostatic valves).

Water radiator classifications

The type of radiators which are normally used can be classified as follows:

According to their configuration:

- Panel radiators

- Element radiators According to the material they are made of:

- Cast iron radiators

- Steel plate radiators

- Aluminium radiators Panel radiators are normally made of steel plate, they have a smooth surface

and can be of several different types:

Water radiator

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- Single panel

- Single panel including a convector

- Double panel

- Double panel including a convector The convector is an element made up of a plate soldered onto the radiator

which increases the transmission of heat.

On the other hand, electric radiators are individual systems based on

independent devices; they are fundamentally used in specific rooms far from the

heat transmission network, which only need to be heated sporadically.

Electric radiator

Heat exchanger units should be energy efficient and of the correct size, and

they should also include good temperature control devices. There are

numerous examples on the market of radiators with different characteristics:

size, material, number of transfer elements, ... .

A comparative study was carried out including some of the most frequently used

types of radiators. The common characteristic between them was their size, and

therefore their heat transfer surface. In the following table we have detailed the

result of the comparison:

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Type of transfer unit Radiator type (W)

Cast iron radiators with four interior columns 2,264

Cast iron radiators with three interior columns 2,026

Cast iron radiators with two interior columns 1,473

Steel radiators 2,219

Aluminium radiators 2,298

Single steel panels 927

Double steel panels with convector 2,669 As we can see from the table, the greatest heat transfer capacity using a

radiator corresponds to double steel panels with a convector, followed by

aluminium radiators.

C2) Other heat emitting elements.

Convectors:

These are similar to radiators, even though the exchange of heat in this case

is exclusively by means of convection. This transfer is based on passing air

through pipes through which hot water is flowing; as a result the air is heated

and distributed using a ventilator.

The disadvantage of this type of installation is that any dust particles, which

are suspended in the air, are moved due to the convection produced by the

transmission of heat.

Air flasks:

These are heat exchanger units made up of a finned thermal exchange battery

module through which hot water is circulating and a ventilator which pushes

the surrounding air through the battery, and therefore heating it. Some of its

advantages are the fact that each device can be controlled independently and

the movement of air which avoids its stratification.

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Fan-coils:

This system is basically the same as that of air flasks, even though the main

difference lies in the temperature of the water, which in this case is lower

(around 50 ºC).

They are normally used when the water distribution installation itself provides

heating in winter and refrigeration in summer.

Photos of different types of heat exchangers

Acclimatizers:

These are final exchange units which heat air and push it into the environment

by means of a network of conduits, regulating the quantity of hot water which

circulates through the heating battery, consequently enabling the temperature

to be controlled.

Radiant flooring:

These systems consist of coiled pipes behind grills in the floor, through which

water circulates at 40/45 ºC. The heat is transmitted by means of radiation and

it is not necessary to increase the temperature as much as in the previously

mentioned systems, thus reducing losses and saving a considerable amount

of energy. Furthermore, the system is regulated automatically due to the

transmission of heat depending on the temperature difference between the

floor and the air in the environment which is to be heated.

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This is a system which provides a high degree of comfort because it emits

heat gradually from the floor upwards, achieving a uniform temperature

throughout the premises.

The main advantage of this system is that it is easy to use renewable energy,

such as thermal solar power, because it operates using water at a low

temperature. The main disadvantage, from a thermal point of view, is that they

are usually systems which have a lot of inertia, and therefore their response

time is quite high, not only in terms of ignition but also when shutting down,

and this makes it difficult to control.

Their use is recommended in those cases where the heating demand is

constant, a situation which can bring about savings of up to 20% with respect

to other systems.

Radiant ceilings: These systems are very rarely used and they work in a similar way to radiant

flooring. The most important difference is that the heat is distributed from the

ceiling downward and therefore the comfort factor is lower.

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B.2.3.2. Energy optimization measures Below we have included an analysis of the main optimization measures.

B.2.3.2.1. Central heating systems control To control a system effectively it is necessary to divide a building into zones, and to carry out the control of each of these in relation to the occupancy, to the area of the building in which they are located and to the activity which is being carried out at each moment.

By installing temperature and interior air quality detectors in common areas, it is

possible to control the entry of exterior air in relation to the demand for

ventilation, thus being able to adjust to the needs and achieve the

corresponding energy saving.

Between 20 and 30% can be saved in terms of energy by using independent

temperature control systems for each zone and by regulating the speeds of the

ventilators or of the water pumps. It is necessary to keep in mind that for each degree that the environmental temperature increases, the energy consumption increases between 5 and 7%.

In those cases where the control system is much more precise and can regulate

the temperature in relation to whether the room is vacant, reserved or occupied,

these savings can reach 40% of the heating and refrigeration consumption.

Management and control systems There is a wide range of regulation and control systems that can be used for

central heating and for the hot water installation, from the simple thermostat,

which operates a pump, to the most complex centralized management

systems which control all of the command parameters set out by means of a

digital display.

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These systems can be classified as follows:

Electromechanic control systems: all or nothing systems, which operate

a regulation element in relation to a command parameter.

Electronic control systems: variable or proportional regulation systems,

which work in relation to a detector which measures the magnitude and

compares it to the command variable, to transmit this difference to the

regulation element which modifies it in proportion to the registered

deviation. The working elements are usually motorized valves in the

water conduits.

Digital control systems: these are direct digital control systems which

use microprocessors to control the distribution and management from a

central computer.

B.2.3.2.2. Improving boiler performance The most common system used to satisfy the central heating needs of

municipal buildings are hot water pyrotubular boilers, one of the most energy

consuming types of equipment. Therefore, an adequate programming and

optimum operation of these devices could bring about a saving in energy and

consequently a considerable economic saving.

The air which is necessary for the combustion

process is pushed by the burner and enters the

boiler at room temperature (below 35 ºC); then it

is expelled through the flu in the form of

combustion fumes (approximately at 140-180

ºC). The heat which was used to heat the air is

not useful heat for heating the water in the boiler.

Conventional boiler

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The difference between the fuel’s Inferior Calorific Power (ICP) is the heat

which is lost in the fumes and the maximum useful heat which can be used in

order to heat the water.

The performance of the boiler can be considered the percentage of that

useful heat with respect to the ICP of the fuel which was consumed.

This performance depends on several factors, among which we can highlight:

Intake temperature of the combustion air.

The higher the temperature of the air which enters the boiler for combustion, the

lower the amount of heat which will be necessary to heat it, and the greater the

performance.

Therefore, the air from the hottest area in the building should be used (South

facing area) and if possible, it should be pre-heated by using any available

residual heat, such as the heat from the exhaust gases of the boiler itself.

Combustion fume discharge temperature.

The higher the temperature of any fumes expelled from boiler, the lower the

boiler’s performance, even though there is a minimum temperature for expelled

fumes, which should not be surpassed by a traditional boiler in order to avoid

highly corrosive condensation (dew point).

So as to reduce the temperature of these combustion gases as much as

possible, it is always recommendable to install a condensing or low temperature

boiler.

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CO2 content in combustion fumes.

The percentage of CO2 in the fumes also influences the performance, because

a low percentage will indicate that the excess of air is higher than necessary for

an optimum performance (due to the fact that the CO2 will be more diluted) and

therefore the useful heat level will diminish, along with the corresponding

reduction in total performance.

For installations which are of a considerable size, it is recommendable to install

a continuous CO2 measuring device (zirconium oxide detectors) in the

discharge gases. There are automated devices which can reduce or increase

the excess of air instantly depending on readings, so as to optimize the

performance.

Maintaining the correct air – fuel proportion is the most important factor with

regard to the efficiency of combustion. An excess of air above that which is

required for a complete combustion increases the sensible heat loss in fumes

and reduces the temperature of the flame.

The correct values for CO2 or for O2 of the combustion gases depends on: the

type of fuel being used and the size of the same, in the case of solids; the type

of combustion equipment being used; the type of boiler room... In any case, as

a mere guideline, the recommended values are indicated in the following table:

Fuel Air excess (%)

CO2

(%)

Liquid fuel 15-25 14-12 Gas fuel 5-15 10-8 Coal 30-50 17-13 Wood 40-70 16-11

Besides the aforementioned factors, it is convenient to take the following

aspects into account:

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It is recommendable to buy a boiler with a well insulated body. Due to the

temperature the boiler body can reach, it is likely that there will be heat

losses by means of convection or radiation; these can be reduced to low

limits (around 0.5%) if the insulation is good. Similarly, adequately

projecting the insulation of the hot water pipes and accumulation tanks is

convenient.

Make sure that the entire length of the interior furnace of the boilers,

where the flame is produced, is corrugated. This corrugation not only

increases the heat exchange surface, but it also considerably reinforces

the conduits through which the combustion gases circulate; this means

that they can dilate as necessary, in a different manner to the rest of the

boiler.

There should be three fume extraction phases, the first through the

furnace, and the rest through the exhaust flue. The performance of those

boilers which are manufactured including two steps (in the furnace and

exhaust flues) is lower due to the smaller exchange surface, and they

deteriorate faster because they are subject to a greater thermal load.

It is convenient for very powerful boilers (above 10 MW) to have two

furnaces (including a burner in each furnace). In this type of boiler, with

only one furnace, it would not only be necessary to have a very large size

of boiler, making the transfer of heat difficult, but also excessively long

flame lengths, producing a high thermal load and thus provoking the

premature aging of the boiler.

There should not be oversized watertight locks in the water chamber,

because they are complicated to maintain and they are prone to leaks

which are difficult to repair.

It is recommendable to purchase boilers featuring modulating burners,

which can adapt the needed generating power to a good performance.

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B.2.3.3.3. Boiler room ventilation In general, in existing buildings, the ventilation of boiler rooms is not adequate,

therefore, below we have specified the minimum characteristics which the

correct ventilation of a boiler room should comply with.

The intake of ventilation air can be carried out by means of direct and indirect

natural ventilation (through conduits and forced). On the other hand, there cannot be any ventilation connection communicating with other closed premises, even if these are directly ventilated. - Direct natural ventilation (through openings):

This type of ventilation can be installed whenever one of the boiler room openings is in direct contact with the exterior. It involves creating openings protected by grills out into the open, also including an anti-bird mesh.

Minimum grilled cross-section (cm2) ≥ 5 x installed nominal power

It is recommendable to make an additional opening to favour the circulation of air in the boiler room.

- Indirect natural ventilation (through conduits):

This can be installed whenever the room does not give out onto the exterior and can be communicated with the outside by means of conduits less than 10m in horizontal length.

Minimum cross-section of the conduits (cm2):

Vertical ≥ 6.5 x installed nominal power

Horizontal ≥ 10 x installed nominal power

- Indirect natural ventilation (forced):

The boiler room ventilation can be forced, by means of a ventilator to push the air into the inside of the room.

Minimum intake flow into the room (m3) ≥ 1.8 x installed nominal power

It would also be essential to install another conduit, on the opposite wall to the air inlets, so as to produce cross-ventilation, due to the fact that if this additional opening is not present any ventilation would increase the pressure in the boiler room.

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A deficient ventilation in a boiler room reduces the useful working life of the

boiler, it can diminish the performance of the installation and can also create

health risks for those workers using the facility.

B.2.3.2.4. Energy sources Below, we have complied a few considerations regarding the most commonly

used energy sources:

Energy sources

Diesel oil: a fossil fuel, manufactured from crude oil. Its combustion gives off the following polluting gases: SO2, CO2.

Its price can fluctuate in a similar way to crude oil.

Propane: a liquid petroleum gas (LPG), with a high calorific power. LPG can be supplied in bulk, and therefore it is necessary to install either a storage tank, or have it piped.

Natural gas: this is the least polluting fossil fuel (its combustion emits less CO2 than other fossil fuels and hardly any SO2), therefore its use is highly recommendable not only from an energy point of view but also in terms of the environment. Natural gas burning boilers are more efficient than the diesel oil equivalents because they can be more precisely controlled.

Electricity: this source of energy is used for all types of heat pumps, heat accumulators which make the most of the price differences between full-price and off-peak electricity tariffs, or radiant panelling and electric radiators as back-up systems for centralized systems.

Renewable energies: solar and biomass. The sources of renewable energies are becoming increasingly more common in municipal centres, and their use is highly recommendable due to their low CO2 emissions and also due to their contribution to reducing foreign energy dependence.

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Natural gas is the cleanest fossil fuel source of energy, as it hardly pollutes and

has a low carbon dioxide content, a characteristic which allows it to contribute to

the reduction of the greenhouse effect, besides having a high calorific power.

From an energy point of view, in terms of the same power, there is gas powered

equipment on the market which has a better performance than those using

diesel oil. This is partly due to the fact that they achieve lower unburnt fuel

percentages thanks to the more homogeneous mixture of fuel and air than in

the case of diesel oil. Another influencing factor is being able to reduce even

more the temperature of the exhaust gases without running the risk of

corrosion. As a result, fuel consumption is reduced and a considerable energy

and monetary saving is achieved.

Therefore, if the installation of a boiler is necessary, and the use of biomass is

not feasible, if possible, it is recommendable that the natural gas or LPG variety

be purchased (even though these are less recommendable due to their higher

price).

B.2.3.3. Hot water for sanitation The most common hot water for sanitation installations consist of a centralized

thermal generator system which includes an accumulator, as shown in the

diagram below:

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M

CENTRAL DE REGULACIÓN

CONTROL

TERMÓSTATO

CALDEIRA

QUEIMADOR

MANÓMETROACUMULADOR

CAMBIADOR PLACAS

VÁLVULA TRES VÍASMOTORIZADA

TERMÓSTATO

BOMBACIRCULACIÓN

VÁLVULAANTIRRETORNO

VÁLVULAANTIRRETORNO

TYPICAL HOT WATER INSTALLATION OUTLINE

As the above diagram shows, the boilers (or heat pumps) produce hot water

which is pushed into the parallel plate heat exchanger; there the cold water,

which normally enters the network from a private well, is heated. The water in

the network heats up and passes into an accumulation tank where it is

maintained at the desired temperature, under no circumstances below 60 ºC, in

order to avoid the risk of Legionnaires' disease.

These tanks serve a double function, on the one hand they maintain the

temperature of the hot water constant, and on the other hand they help to

regulate the varying demand for hot water throughout the day. As a result,

because of the accumulator, the performance of the generator equipment is

more constant, and a better efficiency is achieved. Inside the tank, the

temperature of the water is controlled by means of control systems which vary

the heat contribution of the boilers. Among the equipment which is necessary to

generate hot water for sanitation, besides those mentioned in the central

heating section above (boilers, heat pumps, ...), we can also find accumulation tanks.

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The section dealing with generation should highlight the suitability of active

solar thermal systems in order to pre-heat hot water for sanitation, to such an

extent that municipal facilities should be obliged to use a certain amount of solar

energy, unless otherwise justified. Solar energy is not so adequate for central

heating systems, given that heating is most necessary when there is less solar

energy available, which would bring about excessive overdimensioning.

The same does not apply to hot water for sanitation, which has a relatively

constant demand throughout the year and therefore it should be compulsory to

install solar thermal systems to meet the demand during the summer months

and depending on the climate, to contribute to the same during the rest of the

year. The vast majority of accumulation tanks are made of galvanized steel

plate and they include insulation to maintain the interior temperature.

Hot water for sanitation accumulation tanks

Heat exchangers are used to transfer

heat between the cold water and the hot

water generated in the boiler, and these

consist of stainless steel plates where the

exchange takes place.

Pipe system and heat exchanger

of a hot water for sanitation system.

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These types of exchangers feature a series of advantages as opposed to other

types of systems (such as exchanger tanks) which are summarised below:

Smaller in size.

Easily cleaned.

Possibility to increase the power depending on need.

In the following sections we have included water saving recommendations,

which can reach values of up to approximately 50% of the total energy

consumption, due to the fact that they imply a double saving: the water which is

not used and the energy which is necessary to heat it.

Moreover, it is necessary to totally eliminate any water loss brought about by

leaks or breakages, given that they give rise to a double consumption: on the

one hand because of the pumping equipment and on the other because of the

energy necessary to heat it.

B.2.3.3.1. Using water saving equipment As mentioned above, saving water can mean a reduction in the final energy

cost because of pumping, heating..., besides the environmental benefits that

this implies. Water saving systems should never implicitly mean a reduction in

the level of comfort. There are several solutions available on the market which

make it easy to save water and guarantee the quality of the service and of the

desired comfort. Among them we can highlight:

Nozzle aerators.- These are tap accessories for

washbasins, bidets or sinks which mix air with

water, based on the Venturi effect, consequently

reducing the consumption of water and therefore

the energy necessary to heat it, without reducing

the quality of the service.

Example of a nozzle aerator

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Depending on the pressure of the water, and according to the

manufacturers, these nozzle aerators can diminish the water flow up to 6

and 8 litres/minute, thus obtaining savings which range from 40% in the

case of 2.5 kg/cm2 pressure and up to 30% in the case of 3 kg/cm2 water

pressure.

Water flow interrupters.- They regulate the water flow by means of a

switch, and they manage to reduce the consumption of water up to 40%.

Water-saving showers.- They micronize and accelerate the water by

means of the introduction of air and they reduce the water flow up to

values ranging between 7 and 11 litres/min.

Low-flow taps.- There are several systems featuring water saving taps,

from infrared detection systems, by which the water is cut off as soon as

the user’s hands are moved away, to timers which only remain open

during a predetermined period of time (normally 30 sec.)

WC stop systems for toilet tanks.- They economize up to 70% of the

water. In any case, if the user should so desire, all of the water in the

tank can be flushed.

B.2.3.3.2. General recommendations Apart from all the measures detailed above, there are some measures that can

be put in place with little or no investment, which bring about considerable

energy savings, such as:

Adjusting the control systems so as to maintain the optimum water

mixture conditions.

Example of a water-saving shower

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Insulating the hot water distribution systems correctly.

Sealing all accessories in order to avoid possible water leaks.

Operating by using moderate water pressure.

Avoiding excessively high storage temperatures, although they should

always be above 60ºC.

Installing hot water meters.

Another very important aspect is the detection of leaks for their subsequent

elimination, and in this type of situation it is recommendable to install equipment

which can:

Control water flows depending on zones.

Include the installation of manometers for leak detection.

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SUMMARY OF SECTION B.2.3

- The assessment of residual energy should be a priority, or the use of urban heating, before any other type of heating alternative is taken into consideration.

- When designing the central heating installation, the best options are systems with a good performance with partial loads, which can be maximized using centralized systems.

- The most efficient technology that can be used to generate heat for heating are geothermal heat pumps and high efficiency boilers (low temperature and condensing). Biomass boilers should be encouraged for heat generation.

- The building project should foresee the quantity of heat which is lost through the heat transmission conduits.

- The final exchange of heat should be carried out at the lowest temperatures possible, thus increasing comfort and performance.

- The areas to be heated should be divided into zones, and in each zone measuring, regulation and control devices should be installed in order to adapt the environmental conditions as recommended, avoiding any irresponsible practices by users.

- As far as possible, the spaces to be heated should be limited, for example, by installing suspended ceilings in those rooms which do not need height.

- Solar energy should be harnessed in order to generate hot water for sanitation. Unless otherwise justified, the demand for hot water for sanitation in summer should be completely met using solar thermal energy. During the rest of the year it should operate as a back-up system.

- All taps should be fitted with water saving devices such as: nozzle aerators, water flow interrupters, water-saving showers,...

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B.2.4. Refrigeration installations

(For more information regarding refrigeration installations, please turn to section A.2.5.2.2) Refrigeration needs depend on specific factors such as climate, building

orientation, the quality of the construction materials used, building insulation

and also what the rooms to be cooled are used for.

Given that the final objective of the central heating system and the refrigeration

system is the same – to maintain certain thermal comfort conditions – in

practice, these are both usually designed together, whenever it is necessary to

install a complete refrigeration system for the entire building, which brings about

a certain positive synergy. For this reason, part of the information detailed in the

previous section dealing with heating is also applicable to refrigeration, and also

to the following section dealing with ventilation.

As with the central heating installation, the first step when preparing the

refrigeration project is to calculate requirements. Logically, in order to guarantee

comfort, the final dimensioning of the system will be made considering the most

adverse circumstances, in other words, a maximum internal demand and the

worst environmental conditions. Notwithstanding, the system’s operation at partial loads should be predicted, as this will be the most commonly used, in order to ensure an optimum performance of the equipment in these conditions.

In certain circumstances, this may mean that equipment should be duplicated if

it does not function at an optimum performance under partial load conditions; for

normal conditions it would be enough to operate just one, but whenever the

demand is very high both units would have to be put into operation. This

doubling of efforts would also increase the reliability of the system, given that

any possible failure of either of the devices would not prevent the operation of

the other.

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The most important parameters in so far as determining a comfort situation, are

the following:

- temperature,

- the quality of the air,

- relative humidity.

Not only the way in which the body adapts to climatic conditions in summer, but

also the fact that people wear less and lighter clothes, both mean that a

temperature of 25 ºC during this period of the year is adequate to feel

comfortable inside a building. In any case, a temperature difference of more

than 12 ºC with the outside is not healthy.

On the other hand, the quality of the air depends of several factors and mainly

on using exterior air for its renovation, which should not be lower than 30 m3/h

per person.

In so far as relative humidity, this should be fixed between 30 and 70%.

Once these standard parameters have been defined for all of the rooms in the

building, the appropriate control equipment should be available at the project

and construction phases so as to guarantee these levels of comfort.

B.2.4.1. Classification according to compression Refrigeration systems can be classified according to different criteria, among

which we can highlight the compression system, as this is the most energy

consuming cycle of the entire refrigeration process.

Absorption machines or thermal compression systems: these

consist of a conventional refrigeration cycle in which the compression of

the refrigerating fluid is carried out by means of a thermal process which

needs heat, and therefore it is not necessary to use a compressor.

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Their energy efficiency ratios (EER) vary between 0.5 and 1.7, which is

lower than mechanical compression cycles. Notwithstanding, their use is recommended when otherwise wasted residual thermal energy is available. They are also adequate when the available electric power is

insufficient and it is necessary to generate cold by using a fuel. Their

performance is better at partial loads than at full load.

Similarly, absorption machines are classified according to the auxiliary

fluid used in:

1. Lithium bromide machines. These are relatively cheap machines that

are also rather efficient in so far as acclimatizations (7 - 12 ºC). Their

performance decreases as the demand for lower temperatures

increases.

2. Ammonia-water machines. They are much more expensive. They can

reach much lower working temperatures than the previous examples.

Ammonia is a dangerous product which requires taking precautions.

Absorption machines can also be classified according to the heat source

which is used, into the following:

1. Simple effect: They work by using hot water above 60-70 ºC. Their

efficiency is slightly lower than the standard, the higher the

temperature of the water the higher the efficiency.

2. Double effect: They work by using water vapour at a pressure of 0.25

Mpa. Their performance is better than the standard.

3. Directly flame operation. They function by using some type of fuel,

such as natural gas. It is recommendable to use this variety because

their efficiency is higher than the standard whenever it is necessary to

reduce electricity demand peaks. Moreover, they help to compensate

the consumption of gas throughout the year, because in warmer

periods the consumption of heating is reduced considerably.

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• Mechanical compression systems: they consist of a conventional

refrigeration cycle and a mechanical compressor. The energy efficiency

ratio of these cycles (EER) varies between values of 2.5 and 5.

Similarly, the compressor can be operated by:

1. Electric energy. In general the use of electric motors is

recommended due to their lower maintenance costs.

2. By means of a thermal motor (using diesel oil, LPGs,...). They can be

useful in locations where the available electric power is insufficient,

and obtaining it implies high cost impacts.

Compressors can also be classified according to the motor-compressor

coupling into:

1. Open: The motor and the compressor are independent. The axes

are assembled assuring that the connection is watertight.

2. Semi-hermetic: The compressor and the motor share the axis.

Part of the heat generated by the motor is recovered in the

refrigerating fluid, therefore their performance is better than those

machines which are not hermetic such as the heat pump, but they

are not as good as refrigerating units.

3. Hermetic: The motor and the compressor, apart from sharing the

axis, are housed in the same envelope, so that the recovery of the

heat generated by the motor is greater and therefore the efficiency

as a heat pump increases but as a refrigeration unit decreases.

Therefore, the choice of an open or hermetic compressor should

be motivated by the estimate of time which it will operate as

heating equipment or as a cooling device. If it is only going to be

used as a refrigeration unit, an open compressor should be

chosen.

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Another type of classification for mechanical compressors depends

on the type of displacement, and the following technology can be

highlighted:

1. Alternative: These are made up of a variety of cylinders inside

which there are pistons which move and compress the fluid. They

are similar to car engines except for the arrangement of the

cylinders, which tends to be radial. This type of compressors are

highly efficient at full loads, but they are considerably limited in

several areas at partial loads. They are cheap but they also have a

high maintenance cost.

2. Rotary: The rotary screw compressor consists of two parallel

counter rotating intermeshed helical screw elements. As they

rotate, first of all the space between them increases, generating

volume-increasing cavities to draw in the fluid, and then they

reduce to compress the fluid. Screw compressors are used for

greater powers and they tend to be semi-hermetic. Their efficiency

at full load is more limited than alternative compressors but they

make up for this without any problem by means of a better

performance at partial loads (they are able to regulate from 10 up

to 100% of the nominal load) and because of their lower

maintenance costs.

Spiral or scroll compressors are used for thermal powers of up to

30 kW. The refrigerating fluid is compressed by the volume

variation produced by a spinning spiral. They are hermetic and can

draw and expel the refrigerating fluid simultaneously without

needing a valve. The lower number of moving parts reduces the

deterioration and therefore the working lifetime of this type of

equipment.

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Swing compressors are used with low thermal power equipment

(up to 6 kW). They are rotary and hermetic and they produce a

variation in volume by means of a rolling piston.

3. Centrifuge: This variety usually has several stages therefore they

can achieve great variations in pressure and they are used in high

power equipment.

B.2.4.2. Classification according to construction Refrigeration systems can be individual or they can form part of a centralized system, in which there is a refrigeration system and a distribution network

running to the cold transfer units in each of the rooms. Whenever it is necessary

to acclimatize more than one room, centralized equipment should be chosen, as

they are much more efficient and they avoid problems, such as having to place

the units on exterior walls.

Depending on the type of construction method, individual air conditioning

equipment can be classified as follows:

• Compact systems: They include an evaporator and a condenser, both of

which are inside the same housing. The most common type are fixed in

windows.

• Divided or split systems: They feature an interior unit (condenser) and

another interior unit (evaporator), connected by means of refrigeration

conduits for the refrigerant to circulate through. If the power is the same

as the compact variety, the evaporation and condensing units are larger

in split systems, therefore they can be more efficient than window units.

• Multi-split systems: These are made up of one exterior unit and several

interior units, which is close to the centralized system concept

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Alternative systems:

Evaporating systems: even though in the strictest sense of the term they are not air conditioning units, they can be used to refresh the environment of premises by a few degrees, which may be enough in many cases. Their operating principle is based on making an air current pass over a tray full of water, which evaporates and humidifies the atmosphere, thus cooling it. They are especially adequate for dry interior climates. The consumption of this type of equipment is very low.

Ventilators: a simple ventilator can be sufficient in many cases to maintain an acceptable level of comfort: the movement of air produces the sensation of a reduction in temperature between 3 and 5 ºC, and their electricity consumption is very low.

Operating the equipment in ventilation mode: occasionally, it is enough to keep the equipment in ventilation mode, so as to exchange the air inside the building with the air outside, as long as the exterior is cooler, thus saving considerable amounts of energy (this is part of ‘free-cooling’ which is explained in the following section).

Solar protection: transparent adhesive sheets are available to stick onto the inside of windows in order to diminish the heat flow toward the inside of the building. Moreover, protection such as awnings, curtains, blinds, water curtains, plants, ... It is recommendable to ventilate the building at daybreak when the exterior temperature is lower.

General recommendations:

- Favour the installation of centralized equipment (much higher efficiency at partial loads).

- Chose equipment which includes large capacity condensers and allow the condensation pressure to decrease as low as possible (the consumption of condensers increases 3.5% for each degree increase in condensation).

- In warm and humid climates, use air condensers, instead of wet condensers (by means of water towers or evaporation condensers).

- In forced flow condensers, increase the transfer surface as much as possible in order to reduce the air flow.

- For higher consumptions with large variations in temperature, use double step compression systems, including intermediate refrigeration with fluid separation.

- Reduce the internal load as far as possible, for example by substituting incandescent illumination systems with the fluorescent variety.

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B.2.4.3. Classification according to performance The following functions can be distinguished:

Non reversible systems: this is an example of refrigeration equipment,

which is independent from the central heating equipment.

Reversible systems: these are made up by a single acclimatization unit

which provides heating and refrigeration featuring temperature control

depending on demand.

Heat-cold pumps: capable of producing cold and heat simultaneously.

Below, we have described the first two systems. a) Non reversible systems The operation of a non reversible refrigeration system is shown in the following

diagram.

Evaporador

Dispositivode expansión Compresor

Ventiladorevaporador

+ 3 ºC

Aireimpulsadoó local(15 ºC)

Ventiladorcondensador

Condensador

+ 55 ºC

Aire enviado ó exterior (48 ºC)

Acumuladorlíquido

Refrixerante líquidoa alta temperaturae presión

Refrixerante practicamentelíquido a baixa temperaturae presión

Refrixerante en estadogasoso a alta temperaturae presión

Refrixerante en estadogasoso a alta temperaturae presión

Aireexterior(35 ºC)

Aire extraído do localmais aire exterior (renovación)

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The refrigeration units which are used with this type of system consist of a

compact group, made up of a compression unit, including its corresponding

evaporator and condenser (cooled by either water or air) which is responsible

for cooling a water circuit passing through the different locations to be cooled.

Water condensation systems usually take this liquid from the water mains, or

from a private well. Once it has passed through the condenser and cools the air,

the hot water (which usually reaches temperatures of around 35 ºC) is cooled in

refrigeration towers in order to later return to the condenser by means of

recirculation pumps and thus close the cycle.

Equipment which condenses by means of air is normally located outside so as

to facilitate air circulation through the condenser.

Water only system Air only system

Cooling unit

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“Air only ” systems

When dealing with “air only” systems it is convenient to differentiate those in

which the volume of air is maintained at a constant level and the temperature is

varied, from those systems in which the temperature of the premises is

controlled by modifying the air flow, without needing to vary its temperature.

Furthermore, variable refrigerant volume systems (VRV) are available, which

circulate refrigerant gas through conduits instead of air or water. These systems

feature independent temperature regulation in each room. Consequently they

are capable of achieving a maximum energy efficiency, due to the fact that they

only provide the required energy at any given moment. The energy performance

of this type of system diminishes whenever there is a great difference of height

between the exterior unit and the interior units. Centralized acclimatization

systems including fan coils are capable of adapting the consumption of energy

to the user occupation and use of each of the rooms, therefore obtaining a

considerable energy saving. Acclimatization systems which are distributed by

means of variable refrigerant volume systems, can guarantee that no energy is

consumed whenever there is no thermal demand on the part of the user.

b) Reversible system: Heat pump This is a reversible thermal machine which allows heat to be transferred from a

cold source to a warmer one. In most cases, heat pumps are used not only for

heating, but also for refrigeration. In the latter case, the refrigerant is

compressed by the compressor, and then it is cooled and liquefied in the

condenser (exterior unit) by means of air and water. The aforementioned

refrigerant expands by means of the expansion valve and is transformed into

vapour in the evaporator (interior unit) whilst it absorbs the heat in the air inside

the premises, cooling the room.After the evaporation, the refrigerant returns to

the compressor and the cycle begins once again.

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In the following diagram we have shown the operating scheme of this type of

equipment.

The so-called “inverter” type of equipment, which regulates the power by means

of the electric frequency, saves energy and is more efficient with lower exterior

temperatures.

The main advantage of the heat pump is its high efficiency, for every kWh of

energy consumed, between 2.5 and 5 kWh of heat is transferred. The main

disadvantage of systems using air as a heat source is that whenever they

operate as heat pumps and the exterior temperature is very low, they do not

work very well, because it is difficult for them to capture the heat from the

exterior environment. Therefore it is recommendable to use equipment which

includes a heat source in the ground, given that in winter, when heating is

necessary, the ground is warmer than the environment and in summer, when

refrigeration is necessary, the ground is colder than the environment, and

consequently the efficiency is higher in both cases.

Typical operating scheme including a heat pump

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In large buildings, for example office blocks, which are characterized by their

high internal thermal loads, brought about by illumination, office computer

equipment and their occupation level, and which on the other hand feature

façades with different positionings, there are zones which need to be cooled,

due to insolation and internal loads, whilst at the same time there are other

areas of the building which demand heating. Some types of heat pumps are

capable of producing cold and heat simultaneously, thus solving this situation,

not only in a centralized, but also in a decentralized way.

Another solution is provided by the use of heat pumps to transfer the excess

heat from some areas of the building to those which need heating. This is the

case of highly compartmentalized buildings. Heat pumps using water and air,

are distributed throughout the different rooms and connected between them by

means of a water circuit. The heat pumps located in those rooms which demand

heating, take heat from the water circuit and transfer it to the air. In those rooms

where refrigeration is necessary, the heat pumps evacuate the surplus heat to

the water circuit. The water loop conserves a constant overall temperature,

generally between 20 and 30 ºC. When either the heating or cooling demands

become predominant, the excess of the other production provokes a heating or

cooling of the water loop. For this reason, it includes a compensating device

such as a boiler or a cooling device for example, which inverts one or the other

depending on the demand. The circuit can be open or closed:

• Closed water circuit: If there is a heat surplus, it is evacuated by means

of a cooling tower, whilst if the building lacks heat, the complementary

calorific energy will be provided by a boiler or a heat pump.

• Open circuit: If a supplementary water source is available, either surface

or underground, this can be used in an open circuit in order to provide or

evacuate the heat.

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B.2.4.4. “Free-cooling” and cold accumulation systems On some occasions it is convenient to make the most of the freely available

refrigeration capacity of the exterior air. Therefore, whenever it is necessary to

cool any specific room (meeting rooms, conference rooms, ...) and the

temperature of the exterior air is perfect for refrigeration (during cold periods),

considerable energy savings can be achieved by installing a “free-cooling”

system. This system controls the exterior air flow being introduced depending

on the enthalpy difference between the exterior and interior air, bringing about

the following situations depending on the temperature:

- If the temperature of the exterior air is lower than the temperature of the

air flow of the refrigeration system (approx. 15 ºC), then it is not

necessary to operate the cooling equipment.

- If the temperature of the exterior air is higher than the temperature of

the air flow (approx. 15 ºC) but lower than the temperature of the

cooling system return air flow (approx. 25 ºC), then the production of

cold will be partial.

- If the temperature of the exterior air is higher than the temperature of

the cooling system return air flow (approx. 25 ºC) then it is not possible

to recover any cold and the cooling equipment will have to operate so

as to satisfy the demand.

Air conditioner featuring free-cooling

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Another measure that can help to reduce consumption in certain applications is

thermal accumulation. There is equipment which is capable of storing cold in

the shape of ice in order to use it during peaks in demand. The advantages of

this type of system are the following:

- The consumption of electric energy can be shifted to time periods

when it is not as expensive.

- Given that accumulation is available, the instant power of the

refrigeration equipment can be reduced, therefore helping to

reduce the building’s electricity demand peaks.

- The cold generating equipment will operate in stable conditions,

which will improve its performance and working lifetime, given that

it will not have to be regulating constantly.

Diagram of a thermal accumulation system

This system is especially useful for applications in which there can be very high

specific loads, such as in auditoriums, theatres, ...

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B.2.4.5. Recovering heat from cooling equipment condensation In cooling equipment that condenses by means of water, cooling towers are

commonly used in order to refrigerate the hot water which reaches them.

Subsequently, the cooled water is directly recirculated to the condenser by

means of a pump, starting the cycle once again.

An important energy saving measure in this type of system, would be the

possibility to recover the heat from the condensated water instead of dissipating

it into the environment.

This heat could be used in order to preheat the hot water for sanitation by

means of a water-water exchanger. Consequently, a double energy saving could be achieved: on the one hand reducing the energy which is needed to

obtain the hot water for sanitation and on the other, by reducing the electric

energy consumed by the cooling equipment. Implementing this measure can

obtain energy savings of up to 40%.

At present, acclimatization equipment is available which includes integrated

systems designed to recover this heat. Therefore, in the case of extensions, or

new acclimatization projects or the substitution of equipment, it would be

convenient to chose this type of system.

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- The design of the building as a whole will aim at avoiding thermal loads, by providing elements for protection against solar radiation, such as awnings, blinds, curtains, and by reducing the internal load using high efficiency lamps,...

- The design of the refrigeration equipment should opt for systems with high efficiencies at partial loads, or which can be maximized by means of centralized systems. Inverter technology uses frequency variation for regulation, which improves efficiency.

- Whenever a large amount of residual thermal energy is available, systems using lithium bromide absorption cycles will be given priority, in order to generate cold for acclimatization.

- On the other hand, the most efficient technology will be those systems featuring mechanical compression by means of either an electric motor or by direct flame absorption cycles for those cases where the electric power is not sufficient, or if it is necessary to reduce natural gas demand peaks throughout the year.

- When the cooling equipment is designed only to produce cold, open compressors should be used.

- As far as possible, it is recommendable to use high capacity condensers, refrigerated by air in moderate climates.

- The most efficient transmission system is that which is of the Variable Refrigerant Volume variety, given that it only provides the energy which is demanded in each room.

- The building project should foresee the insulation of cold transmission conduits.

- The areas to be refrigerated should be divided into zones, and in each zone measuring, regulation and control devices should be installed in order to adapt the environmental conditions as recommended, avoiding any irresponsible practises by users.

- The refrigeration system should enable the enthalpy of the exterior air to be harnessed, reducing the consumption of refrigeration whenever the air is below 25 ºC (with freecooling, or by operating in ventilation mode). Furthermore, it should allow for the exploitation of the energy from the renovated air by means of regeneration systems.

- Cold accumulation systems can help to reduce the power of the equipment which has been installed, and the running of these in more highly efficient conditions.

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B.2.5. Ventilation

(For more information regarding ventilation equipment, please turn to section A.2.5.2.3) The demand for fresh air by those people who use a building should be planned

in terms of health and comfort. In general, there are no activities which pollute

the air in municipal buildings and premises so therefore the sources which

deteriorate the quality of the interior air will fundamentally be those caused by

the breathing of any occupants and the emission of smells.

By means of breathing, CO2 is given off and the emission rate depends on the

activity being carried out by the occupants. The concentration of this substance

should be controlled, given that in excess it can cause headaches, dizziness

and breathing problems.

In terms of the concentration of smells, this can lead to a considerable increase

in the demand for air renovation. To this effect, the current tendency to prohibit

smoking in all Public Administration premises has made a positive contribution,

because the smell of people’s body odour is responsible for this type of incident.

For example, in so far as sports centres, where an intensive physical activity is

carried out and there are also sources of vapour, it would be necessary to

ensure that the concentration limits are within an acceptable range.

The parameters which are commonly used to determine the quality of interior air

are the following:

Water vapour concentration.

CO2 concentration.

Concentration of smells.

Concentration of any other type of polluting substances.

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For this reason, a minimum renovation flow has been established, expressed in

cubic metres, albeit per person, per surface or volume unit, or in terms of

renovations per hour. The inverted calculation of this quantity is interesting

because it can give us an idea of the average time that air remains in the

premises.

The renovation of the interior air of a building depends on the opening of

windows and doors in those rooms which are in contact with the outside, in

order to be able to introduce air and at the same time to provide evacuation

routes for the polluted interior air, making it possible to create an air flow

between the sides of the buildings to produce cross- or complementary

ventilation.

The renovation of the air can also be carried out by mechanical means, by

using a system of machines and/or conduits. This procedure is important

because it means that a minimum renovation rate can be guaranteed in all the

premises. In so far as the speed of the air, it would be convenient to establish

an optimum speed, given that an excessively high air speed can affect the

thermal comfort sensation by helping to cool the air by convection, whilst an

excessively low speed can create areas of stagnant air in rooms with not

enough renovation.

In order to achieve an energy efficient system, it is recommendable to design

systems which can modulate the ventilation flow depending on the interior and

exterior conditions (occupation, activity, ...).

It should also be kept in mind that during summer months the renovation rate

will probably have to be increased, allowing the excess heat and water vapour

to dissipate.

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When the interior temperature is the same or slightly higher than outside, the

ventilation system can be used without any drawback, as long as there are no

air currents that can inconvenience users. Whenever the exterior temperature is

considerably higher than inside, it would be convenient to moderate the

renovation flows, whereas at night and during the early hours of the day, the

opposite strategy is necessary, thus increasing the renovation rate. In general,

this operating method will be adequate in those climates where there are

considerable fluctuations in temperature between day and night.

The movement of air which is necessary for natural ventilation comes about by

means of the wind against the building’s façades, generating cross-ventilation,

either because of the difference between the density of the interior and exterior

air, which brings about a difference of pressure, bringing about the movement of

rising air or chimney draught.

The wind is the most adequate force to generate natural ventilation, therefore it

would be necessary to know the wind direction tendencies of the area where

the building is to be located, so as to correctly harness the effect of this

element, taking into account that orographic obstacles in the surroundings can

modify the speed of the wind.

The wind creates pressure on the façades which it blows against directly, and

suction on the side and rear façades.

Whenever the ground plan of a building is rectangular, it is recommendable to

position the main façades facing the wind, whilst for buildings with square

ground plans, the optimum positioning is when the ground plan is turned 45º,

thus positioning one of the corners facing the direction of the wind.

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B.2.5.1. Recovering heat from ventilation air

When the interior temperature of the building is much higher than the exterior

environment, an obligatory efficiency measure in centrally heated buildings,

which include controlled ventilation, is to make use of the heat from outgoing air

in order to preheat the incoming air. The same thing happens whenever the

exterior air is at a much higher temperature than inside, in this case the

outgoing air is harnessed to cool the incoming air. These heat exchange

systems should guarantee the appropriate use of at least 50% of the available

energy.


• The use of a natural ventilation system is recommendable in moderate

climates and in small buildings.

• In extreme climates and large complexes, artificially controlled

ventilation makes it easy to regulate and control the environmental

conditions and to allow for the installation of efficiency techniques.

• In those buildings with artificial ventilation, the design should include

regeneration systems which enable at least 50% of the useful thermal

energy from the renovation air flow to be exchanged.

• Furthermore, the artificial ventilation system should allow the ventilation

flow to be regulated depending on the occupation level.

• It is recommended that the number of openable windows should be

limited in those areas with artificial ventilation.

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B.2.6. Artificial illumination equipment

The basic purpose of any illumination installation consists of providing the

appropriate illumination for the task of seeing, and the objective is for people to

see adequately and comfortably, whilst going about their activities with the

necessary precision and speed.

The use of natural light or a combination of this with artificial illumination,

favours a reduction in those stress levels which are associated to the

development of different activities. Furthermore, windows and illumination

systems using natural light not only influence the distribution of light, but they

also influence the building’s energy balance.

Apart from reducing the lighting consumption, the use of natural light as a

means of illumination can also help to reduce the heating needs of the building

during winter periods. In summer periods, the reduction of the need for artificial

illumination, reduces the internal load, and consequently contributes to energy

saving in terms of refrigeration.

A correct building design, as mentioned in the corresponding section above,

would contribute to the maximization of the natural light contribution, which does

not mean that this type of illumination does not need any type of control, albeit

either by manual means, such as curtains, blinds or screening systems, or

automatic means instead, limiting the direct or undesirable indirect effect of

sunlight.

Notwithstanding, even when buildings feature the most appropriate illumination

possible by means of natural light, there is always the need to complement or

substitute it (whenever it does not exist) by using artificial lighting.

The basic elements of an artificial illumination system are the following:

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• Luminaire: Any device which controls the distribution of light emitted by

the lamp.

• Lamp: Any device which transforms electric energy into light and heat.

• Auxiliary regulation and control equipment: Devices which modify the

characteristics of the electric current in order to make them suitable to

operate the sources of light.

B.2.6.1. Lamps

The most commonly used types of lamps are the following (for more

information please turn to section A.2.3.2 of this guide):

• Incandescent lamps: This is the oldest and most commonly used

commercially available lamp. Its average working lifetime is of around

1,000 hours and its average luminous efficacy ranges between 10 and

12 lumens/watt. These lamps emit about 20% of the energy they

consume in the form of light and the remaining 80% is lost in the form of

heat, increasing the temperature of the room.

• Halogen lamps: Halogen lamps are a variation of the incandescent

lamp. The advantages of this lamp are: longer working lifetime, better

luminous efficacy (18/22 lumens/watt), and a smaller size.

• Mercury vapour discharge lamps: Discharge lamps consist of a tube

which contains mercury vapour. This type of lamp includes the

following:

- Fluorescent - High pressure mercury - Blended - Metal halide

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• Sodium vapour discharge lamps: In this case, the discharge tube is

filled with sodium vapour.

• Induction lamps: The advantages of this variety include the following:

- Longer working lifetime

- Comfortable light without oscillations

- Ignition without flickering or flashing

- Luminous flows of up to 12,000 lumens

- Luminous efficacy of 80 lumens/watt

• Low consumption lamps: This is a variation of fluorescent tubes

which have been adapted to replace incandescent lamps without any

type of installation. The advantages of these lamps are the following:

- Longer working lifetime (up to 15,000 hours)

- Higher luminous efficacy

- Smaller size

B.2.6.2. Regulation and control equipment Incandescent lamps, halogen and blended light lamps do not need any type of

auxiliary equipment to be connected to the electric mains supply, due to the fact

that their characteristics mean that the intensity and voltage which pass through

them are proportional. With regard to discharge lamps, the relationship between

the intensity and voltage which pass through them is not proportional, that is to

say: the voltage almost does not depend on the current which goes through it,

therefore, in order to avoid fluctuations in illumination and for it to function

properly, it is necessary to include some type of current stabilizing device.

The devices which are normally used to stabilize the current are conventional

starting devices which control the ignition.

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The most commonly used auxiliary equipment are ballasts and starting devices:

Ballasts: The reactants or ballasts are accessories which are used in

combination with discharge lamps and they limit the current which

circulates through them in order for them to work properly. Moreover,

they supply the necessary ignition current and voltage in each case.

Starting devices: this type of equipment is necessary whenever the

voltage needed for ignition is very high.

For more information, please turn to section A.2.3.4.

B.2.6.3. The importance of colour The level of illumination in a room also depends on the colour which has been

chosen for the walls. As a result, more or less light will be reflected, depending

on the colour which has been chosen, making the quantity of light in the room

vary.

Below we have detailed a comparative table with a series of colours and their

reflection rate:

COLOUR % of light

reflected on the wall

White 95% Yellow 94% Ivory 88%

Sky blue 85% Green 79% Pink 71%

Beige 68% Orange 62%

Blue 41%

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Consequently, it is recommendable to keep in mind that the walls and furniture

which are light in colour favour a better illumination efficacy when compared to

walls and furniture of a dark colour, which will mean that any source of light will

have to be turned on for longer periods of time, thus increasing the electricity

consumption for illumination.

B.2.6.4. Choosing lamps

In the following section we have highlighted some types of lamps which are

usually used in situations where they are not the most energy efficient

alternatives. Regarding of all these situations, we can find more information in

sections A.2.2 and A.2.3, nevertheless, taking into account how common these

situations are, we think it appropriate to also highlight them in this section.

Similarly, below we have detailed a series of general recommendations which

are necessary in order to reduce the electricity consumption for illumination.

Controlling excessive artificial illumination levels.

Using paints and colours which favour energy saving in so far as

illumination.

Adequate and regular maintenance of the illumination system.

Cleaning lamp shades.

Using timer programmes.

Reducing any unnecessary exterior impact lighting (billboards, excessive

lighting on façades and balconies).

Using presence detectors in common areas: corridors, unused

thoroughfares.

Installing localized illumination which, apart from creating a welcoming

environment, can help to reduce consumption, given that many times it is

not necessary to light the entire room.

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Installing light intensity regulators in rooms, which can mean a reduction

in energy expenditure and the advantage of being able to adjust the

illumination level at any given moment according to need.

Installing timer switches to turn lights on and off in common areas.

B.2.6.4.1. Compact fluorescent lamps (low consumption)

As mentioned above, incandescent lamps dissipate 80% of the energy they

consume in the form of heat and they use only 20% of the remaining energy to

illuminate. Therefore it is advisable to replace this type of lamp for others with a

higher luminous efficacy, such as low consumption lamps.

This simple measure can mean an energy saving of up to 80%, maintaining the

same illumination and comfort levels. The investment which changing this type

of lamps implies is returned in a short period of time.

In the following table we have included a comparison of the power of both types

of lamps for the same illumination levels, highlighting the energy saving that can

be obtained by their replacement.

Incandescent Power (W)

Low consumption Power (W)

Luminous flux (lm)

Energy saving (%)

Energy saving (kWh/year)

40 9 400 78 33 60 11 600 82 52 75 15 900 80 64

100 20 1.100 80 85 120 23 1.500 81 104

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B.2.6.4.2. Discharge lamps The use of this type of lamp is recommendable in those areas where a good

colour rendering index is not necessary. With this type of system an energy

saving of up to 35% can be obtained.

Below, we have included a table summarizing the average saving that can be

obtained by substituting lamps, not only in exterior but also in interior lighting.

EXTERIOR ILLUMINATION

INTERIOR ILLUMINATION

B.2.6.4.3. Improvements to fluorescent lamps In general, fluorescent lamps are used in areas where there is a need for good

quality light and where the lamps are rarely turned on and off. In the case of

fluorescent lamps which are turned on for a long number of hours every day, it

is recommendable to replace conventional ballasts with the electronic variety.

With this measure it is possible to obtain a reduction in consumption and the

working lifetime of the lamps is increased, therefore maintenance and

replacement costs are reduced (for more information, please turn to A.2.3.2.).

Lamp Substitution Energy saving %

Mercury vapour High pressure sodium vapour >12

Conventional halogen High pressure sodium vapour 78

Conventional halogen Metal halide 70 Incandescent Compact fluorescent 80

Lamp Substitution Energy saving %

Incandescent Compact fluorescent 80 %

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Below we have detailed the other advantages of this system as opposed to a

conventional one.

Improvement of lamp and system efficiency.

Absence of flicker and stroboscope effects.

Instant ignition without the need for any type of independent starting

device.

Increase in the working lifetime of the lamp.

Excellent possibilities in terms of the regulation of the luminous flux.

Power factor close to the standard.

Simpler installation.

Lower increase in temperature.

Absence of humming or any noise.

Less weight.

B.2.6.4.4. Exterior lighting When dealing with this type of lighting, it is recommendable to install lamps

which are highly efficient in so far as luminous efficacy, such as high pressure

sodium vapour lamps, with which a large amount of light can be obtained with a

low consumption of energy. Similarly, it is interesting to consider the installation

of a flux reduction system (double level), which will allow the illumination level

to be regulated in accordance to the time of day, for example reducing the

luminous flux to 40% between one and six o’clock in the morning, consequently

obtaining a reduction in energy consumption and therefore in the cost of the

equipment. Another type of energy saving measure for exterior lighting is the

installation of astronomic clocks, which are automatic solar switches designed

to turn on and off exterior lighting coinciding exactly with daybreak and sunset

every day. Between 10 and 20% can be saved by using these systems. (For

more information, please turn to section A.2.2.2.5)

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- When designing illumination equipment, an adequate division of the

available space should be carried out so as to avoid excessive

consumption with partial occupation.

- In premises with high ceilings, the required level of illumination should

be located in the working area.

- The use of natural light should be maximized as much as possible,

using regulation systems which are controlled by photocells in areas

close to windows.

- In general terms, the most efficient technologies are the following:

- Fluorescent or low consumption lamps for interiors and low

heights.

- Sodium vapour or metal halide lamps for interiors and high

ceilings depending on the required colour rendering index.

- Sodium vapour lamps for exteriors.

- In every case, the sources of light should include high efficiency

luminaires, with multiple options to direct the light onto the required

areas.

- In areas which are used sporadically, (garages, storerooms, toilets, ...)

it is convenient to install automatic shut-off systems such as presence

detectors or timers.

- Electronic regulation equipment can help to obtain considerable energy

savings as opposed to the electromagnetic variety.

- With regard to exterior security lighting systems, it is recommendable to

use double level illumination levels and astronomic clock switches in

order to regulate ignitions and shut-downs.

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B.3. VIABILITY ANALYSIS B.3.1. Active solar energy systems

Active solar energy systems are all those installations which are exclusively

dedicated to harnessing solar energy. At present, there are two different

applications:

- Thermal solar systems: which are mainly used to heat water.

- Photovoltaic solar systems: which are used to generate electric energy.

The performances of both types of technology are increasing slowly but

constantly as time passes, therefore it is likely that their applications will grow

quickly. At present the uses which are considered of interest, as well as their

advantages, are the following:

a) Thermal solar energy:

As mentioned above, this variety is mainly used to heat water, therefore it is a

technology which is ideal for heating hot water for sanitation and for other uses

in which heat is necessary, even though it may be in small quantities, at low

temperatures on a daily basis or fundamentally during the summer months.

The application of this type of technology should be obligatory in facilities such

as heated swimming pools and for preheating hot water for sanitation when

using equipment with a fixed minimum consumption, except in those cases

where it can be justifyingly demonstrated that there is not sufficient space for

their installation, a situation which can be common in the middle of a city, due to

the positioning limitations of the radiation harnessing system and the shadows

which are cast by other buildings.

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In general, the advantages of thermal solar energy are the following:

- Harnessing a renewable energy source and therefore saving another

type of fuel which is not as environmentally friendly.

- Reduction of foreign energy dependency.

- Decentralized generation whereby the energy transport impact is

minimized (electric power lines, oil tanker accidents, ...) And the only disadvantages are:

- An increase in the initial investment, because due to the

unpredictable nature of the weather, it is not possible to manage

without a back-up system to supply energy. In terms of construction, there are two slightly different technologies which

feature the following characteristics:

- Flat solar panel installations.

- These enable water to be heated efficiently up to approximately 50

ºC, always depending on the weather.

- Investment, about 600 €/m2, producing around 580 kWh/year,

depending on the weather in the area.

- Investment return periods around 12 months, depending on their

correct application and the legal requirements and subsidies in the

area.

- Robust installations.

- Vacuum tube installations.

- They can heat water up to temperatures around approximately 90

ºC, always depending on the weather, therefore they can be

commonly used for more applications than those mentioned above.

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- They are more expensive installations, with investments around

1,000 €/m2, producing around 750 kWh/year, depending on the

weather in the area.

- The return period on the investment is approximately 15 years,

depending on their correct application and the legal requirements

and subsidies in the area.

- Very vulnerable to vandalism.

The installation of thermal solar equipment consists of the assembly of the

harnessing surface (solar panels), of the accumulation and distribution system,

as well as any other auxiliary equipment, which makes the whole process

expensive and complicated in a building which has already been constructed.

For this reason, it is recommendable to carry out the installation when the

building is being constructed (or reformed); therefore the design of this system

should be included in the corresponding technical project of the building.

To this respect, the integration of solar energy into the building tends to imply

the substitution of some type of basic constructive element by harnessing

elements (panels). In those cases where it is impossible to carry out the

installation at the same time as the construction or renovation of the building, it

is recommended to at least make a pre-installation for the aforementioned

system (this is obligatory in the legislation of some states). Therefore, at any

moment it would be possible to carry out the installation with a minimum of work

and at a much lower cost than if the pre-installation had not been carried out.

A thermal solar energy pre-installation consists of any work and preparation

carried out in a new building which allows for the harnessing of solar energy

depending solely on the choice of the final users; in general, it is enough to

consider the following aspects:

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• Fixing of brackets on the roof, if this can be the location or position for

the installation of the solar panels.

• Installation of pipes for the primary circuit from the roof (or wherever the

panels are located) to the boiler room.

If necessary, enough room to install an accumulator and the remaining auxiliary

equipment. If the conventional system already includes an accumulator, it would

be interesting to make it compatible with a subsequent solar panel installation.

b) Photovoltaic solar energy:

Photovoltaic solar energy systems consist of the harnessing of the energy from

the Sun in order to generate electric energy. There are two types of photovoltaic

installations:

- Isolated from the electrical mains. - Connected to the conventional electrical mains.

Those installations which are isolated from the electrical mains include the

following characteristics:

- The possibility to supply electricity in areas which are difficult to access or

where consumption is low, where installing electric powerlines would be

very expensive, in an economic and environmental sense.

- The panels only produce energy during those hours with sunshine but

notwithstanding energy is generally used during 24 hours a day, thereby it

is necessary to install an accumulation system. Thus, during those hours

of sunshine, it is necessary to produce more energy than is consumed, so

as to accumulate it and be able to use it when it cannot be generated.

- Very autonomous, if we compare it to a small diesel oil generator, which

would need regular refuelling which implies greater maintenance costs.

- It uses a renewable source of energy which is environmentally friendly

once installed.

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- Reduction of foreign energy dependence.

- High initial investment, approximately 12,000 €/kW.

The return period on the investment for an isolated photovoltaic solar installation

depends a lot on the application and use, thus in many cases it is cheaper to install a

complete system than any other alternative, and the return period would then be

immediate.

The main applications of the systems which are isolated from the electrical mains are:

supplying electricity to isolated homes, illuminating streets and roads, signage (airport

beaconing, road and port signs, etc.), telecommunications (television booster stations,

mobile telephone antennae, radio equipment, etc.), ...

In so far as photovoltaic solar installations connected to the electrical mains, the

advantages it provides are the following:

- Decentralized production of electric energy, therefore in spite of faults in

the transportation network or supply of electric energy the system can still

work in isolation.

- The demand for energy from the services sector in the European Union is

growing at a considerable rate, therefore the integration of photovoltaic

systems in buildings, with energy contributions during peak hours,

contributes to the reduction of daytime energy production.

- It uses a renewable source of energy which is environmentally friendly

once installed.

- Reduction of foreign energy dependence.

- High investment per kW of installed power (approximately 6,000 €/kW)

- The production depends on the weather.

In order to achieve a better integration of the photovoltaic elements in buildings

it is necessary to keep them in mind from the very beginning of the design of the

construction. As a result, the exterior appearance of the building can be

improved along with the cost, because conventional elements can be replaced

by using photovoltaic elements.

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The most common building integration applications are the following:

• Façade coverings

• Curtain walls

• Façade sunshades

• Pergolas

• Flat glass roofs

• Skylights in roofs

• Sheets in windows

• Tiles

For those applications which have special architectural restrictions, a common

solution is encasing conventional cells in glass – glass. These glass – glass

modules are very appropriate for this type of applications because, besides

totally fulfilling the technical and esthetic requirements of the design, they also

allow for certain levels of semi-transparency which helps to increase the

luminosity inside the building.

The return period on the investment for a photovoltaic solar power plant

connected to the electrical mains depends to a large extent on the legal

requirements and subsidies of the area, as well as the weather and the use of

the energy which is sold to the mains network. It is also of vital importance how

easy it is to access economic financing in order to support the investment.

As a general guideline, in some European countries the return period is around

10 years, but the possibility of variations between countries is very high.

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- Thermal solar energy is an ideal technical solution for heating water for

sanitation. Its use for this purpose is considered obligatory in all public

administration buildings. Unless otherwise justified, the supply of hot

water for sanitation should be totally guaranteed during the summer

months by means of solar energy.

- Isolated photovoltaic solar energy systems are appropriate to satisfy

reduced electricity consumptions, avoiding the investment and

environmental impact brought about by a connection to the general

supply mains. For example, its use is recommendable for low power

street lamps in isolated locations.

- The installation of photovoltaic solar energy systems connected to the

mains contributes to the reduction of fossil fuel consumption, therefore

municipal premises should use them in order to set an example for

others.

- Due to the progressive increase of the efficiency of solar applications, it

is recommendable to take into account any possible future uses when

designing a building, especially for those buildings whose South facing

façades are not shaded.

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B.3.2. Central or urban heating systems Central or urban heating systems refer to the possibility of carrying out

installations to distribute heat which enable various buildings to be supplied by

means of hot water or vapour, thus avoiding the direct transportation of energy

products such as biomass, coal, diesel oil or natural gas, ... This type of

installation features considerable advantages, such as the following:

- This is a system which enables residual heat from industrial processes near

population concentrations to be harnessed. In many industrial processes

there is a demand for very high temperatures, and there are also

considerable heat dissipations at low temperatures (80 ºC, 60 ºC), which are

neither useful nor usable during the process itself; nevertheless they are

adequate for acclimatizing housing. These systems are especially profitable

in cold climates, and with high consumptions which would enable the

distribution system costs to be paid off.

- When there is no free residual heat available, a centralized system has the

advantage that dozens or hundreds of small boilers with average

performances are replaced by one or several larger boilers with much higher

power and better performances. Moreover, these larger boilers are managed

by professionals and can be designed to use residues such as locally

available forest or industrial biomass, which smaller boilers would not be able

to use.

- Centralized installations allow for a greater control of performance and of any

environmental effects in comparison to smaller versions.

- Centralized installations reduce the risk of accidents, not only with regard to

the transportation of energy products, such as diesel oil or natural gas, but

also in terms of the irresponsible practices that users could carry out with

regard to these products.

- They have inferior costs than individual systems. To this respect, it is worth

mentioning the importance of installing individual consumption meters.

Besides the possibility of introducing a fixed price per user, the economic

cost should always be billed depending on individual consumption.

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Disadvantages:

- The most important disadvantage of centralized installations is the

coordination which is necessary for them to be put into practice. Public

administrations should promote their installation and municipal buildings

should also encourage them by subscribing to these systems as if they

were normal consumers.

For example, if the council is planning a multi-sports pavilion with a heated

swimming pool in an area in which several buildings are going to be constructed

in the near future, they should look into the possibility of making an overall

heating installation which could meet the thermal energy needs not only of the

pavilion, but also of the new buildings which are going to be constructed, and

even of any which have already been built if they have a centralized heating

installation. In this example it would also be interesting to propose a centralized

heating installation which includes a co-generation plant.

Whenever there is a great demand for heating in a reduced geographical area,

it is recommendable to encourage centralized heating systems which include

individual meters.

SUMMARY OF SECTION B.3.2 - Central or urban heating makes it easy to harness any residual

endogenous energy and/or fuels such as biomass.

- In so far as urban installations, high efficiency rates can be achieved

thus reducing the cost for the end user.

- Whenever possible, public administrations should make use of

centralized or urban heating systems.

- Whenever there is a great demand for heating in a reduced

geographical area, it is recommendable to encourage centralized

heating systems which include individual meters.

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B.3.3. Cogeneration systems

Cogeneration is defined as the local and simultaneous production of electric

and/or mechanical energy and of useful thermal energy by using the same

source of primary energy.

An example that can help to understand the concept is a conventional car, in

which one fuel (petrol, diesel oil, biodiesel, ...) is consumed in order to make the

engine run; on the one hand, the result is that we can move the car (mechanical

energy), and on the other hand we can obtain heat from the refrigeration of the

engine or of the exhaust fumes (thermal energy) in order to acclimatize the

inside of the car. Moreover, in this case electric energy is also generated and

used to recharge the battery and in those cases in which the appropriate

equipment is available, it can also generate cold.

Cogeneration is one of the most efficient solutions to reduce the energy costs

on account of the elevated energy efficiency which can be obtained by

harnessing the heat which is normally residual. The same process which takes

place in a car, but on a much larger scale, can be put into practice to

acclimatize large office complexes, for example those used by different

administrations (the mechanical side of the motor would be used to move an

alternator to generate electricity for consumption or to supply the electric mains

network, and the thermal side to acclimatize the facilities).

Cogeneration is profitable in installations which have a high heat consumption

during a long period of time throughout the year. The return periods on the

investments stand at around 5 years, even though they depend largely on the

specific installation, local legislation and the evolution of those fuels which are

used.

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Among those advantages associated to a cogeneration facility, it is worth

highlighting:

- It diversifies energy supply sources.

- It guarantees the supply of electricity, in the face of possible faults in

the distribution network.

- It increases the efficiency of the use of energy: a lower consumption

of fuel and less CO2 emissions, therefore it contributes considerably

to sustainable development.

- It affects the competitiveness of a company, because it reduces

energy costs.

- It diminishes the primary energy consumption of the country.

- It reduces losses caused by transportation and distribution, as it

moves the generation closer to the consumption.

- It generates employment and strengthens technology sectors

associated to cogeneration.

The following could be considered disadvantages:

- Uncertainty with regard to the evolution of energy prices and

management difficulties apart from those of the original activity.

- An increase in local pollution.

There are several types of cogeneration technology, the most common being:

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COGENERATION TECHNOLOGY - Alternative internal combustion engine

The main advantages of this type of technology are its flexible uses, high

electric efficiency and reduced investments costs (around 700€ per installed

kW, including all other costs except the plot of land, valid for installations of

more than 1 MW of installed capacity of electric power).

They provide three thermal energy sources:

- Refrigeration of the engine lining and oil at an approximate

temperature of 90 ºC.

- Air refrigeration of the engine load at an approximate temperature of

35 ºC.

- Heat from the combustion exhaust fumes at an approximate

temperature between 300 and 500 ºC.

- Gas turbine Its main characteristics are a high heat/electricity ratio, whereby it is adequate

for uses which do not consume a great deal of heat. Furthermore, all the heat

available comes from the exhaust fumes and it is at a high temperature,

between 400 and 500 ºC depending on the specific installation. Another

characteristic of the exhaust gases is that they are rich in oxygen (15%) and

they are therefore adequate for post-combustion in a boiler, thus improving its

performance.

The investment is around 800 € per installed electric kW, including all other

costs except the plot of land, valid for installations of more than 2 MW of

installed capacity of electric power.

- Vapour turbine

The main advantage of vapour turbines is that combustion takes place in a

boiler which is not integrated inside the thermal machine, and therefore this

means that more heterogeneous fuels can be used, such as biomass, solid

urban waste, coal, ...

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The investment is approximately 1,400 €/kW, including all other costs except

the plot of land, valid for installations of more than 2 MW of installed capacity

of electric power. In the following table, we have included the main

characteristics of each of the most common types of technology that can be

used in a cogeneration plant.

Vapour turbine Gas turbine Alternative engine

Power 500 kW – 1500 MW 500 kW – 300 MW 50 kW – 30 MW

Electric efficiency 15-40 % 20-40 % 30-45 %

Thermal energy Vapour (3 – 25 bar) Gases with surplus air

500ºC

Hot water and gases

at 375ºC

Operating system Continuous to nominal Continuous to nominalDiscontinuous and at

partial loads

Electric/thermal

energy ratio 0.15 0.51 1.66

Cost 1,400 €/kW 800 € /kW 700 €/kW

Working lifetime 250,000 hours 120,000 hours 60,000 – 80,000

hours

Resources

(programmed stops.) 99% 98.5% 93%


- Cogeneration is one of the most efficient solutions to reduce the energy costs on account of the elevated energy efficiency which can be obtained by harnessing the heat which is normally residual.

- Cogeneration is profitable in installations which have a high heat consumption during a long period of time throughout the year.

- Cogeneration guarantees the supply of electric energy, in the face of a possible fault in the supply network.

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B.4. PROJECT VIABILITY REPORT The constant growth of services and interaction demanded of a building can

lead to the designs of these being more and more complex. It is difficult for a

technician or for a specialized report into the distribution of spaces and the

calculation of structures to be qualified to evaluate the best alternatives with

regard to acclimatization, illumination, ... At present, when acquiring or

designing a building, the first aspect (available space) is given priority over the

second (efficiency) due to the fact that it is more visible for the majority of users,

and it is once the building has already been constructed or bought that

operating and maintenance problems become evident.

Therefore, in buildings of a certain importance, for example, larger than

1,000m2, it is recommendable for the commissioning body to contract the revision of the project design by a technician or company specializing in installations, which is independent from the project designer, before the definitive approval of the same. From an energy efficiency point of view, and

as the first step to obtaining the energy efficiency certificate in line with Directive

2002/91/CE, it would be convenient for a certifying company to verify the

derived energy efficiency calculation of the building which has been designed

and in the same procedure they can include any recommendations to improve

the cost-efficiency relationship of the energy efficiency.

In council buildings it is relatively common to redistribute offices and in some

cases even change the type of use, therefore it is convenient to keep in mind

these circumstances and to design installations that can allow for this type of

flexibility as far as possible.

It also seems essential to verify that the spaces which have been designed to

be used for equipment (boiler rooms, meter rooms, wiring conduits, ...) are all

functional and reasonable enough to be subject to possible modifications that

may be necessary at a later date.

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SUMMARY OF SECTION B.4

- The building project specifications should include the justifications for all

the solutions which have been put into practice. It is not enough to simply provide a compilation of plans and instructions; what can really guarantee the work that has been carried out for the preparation of a project and can also increase its quality, is the justification for the solutions put into practice and their specific adaptation to the situation.

- The construction of a building is increasingly demanding, therefore,

once the project has been completed, and before the definitive approval of the same by the contractor, it is essential that it be revised by a qualified technician or company, specialized in installations and independent from the project designer.

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B.5. CONSTRUCTION PHASE If the design phase has been carried out in a responsible manner, dedicating

the necessary time, during the construction phase it should only be necessary

to certify the fulfilment of the approved project, making sure that the quality of

the elements and their installation meet the project guidelines. If during the

construction phase it becomes obvious that the construction does not meet any

of the points laid down in the technical project, the technical management along

with the certifying company should evaluate the effect on the energy efficiency

of the building, leaving a written record in the building register. If the effect of

the resulting modifications is considered serious enough, the project should be

reconsidered as a whole before continuing with the construction.

If the steps recommended in this guide are followed during the preliminary

building design stages, the outcome can be nothing other than an Energy Efficiency Certificate with the highest possible rating. Once again we would

like to emphasize that public administrations cannot ignore their obligation to be

an administrative example in spite of the fact that this may mean additional

installation costs, which will eventually be paid off during the working lifetime of

the building, as mentioned above.

SUMMARY OF SECTION B.5 - The same independent company specialized in installations which

revised the project, or another similar company, should be contracted

beforehand in order to advise the promoter in the face of any possible

changes that may be necessary whilst the project is being carried out.

- The result of the construction of a public administration building can be nothing other than an Energy Efficiency Certificate of the highest possible rating for the construction.

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C. BUILDINGS CATALOGUE

C.1. SPORTS FACILITIES Sports facilities include a series of premises dedicated to leisure and sporting

activities which are offered by a council. The energy consumption of these

sports facilities makes up approximately 10% of the council’s total energy

consumption.

Generally, in order to be able to carry out recommendations which are common

to all sports facilities, this study focuses on municipal pavilions and swimming

pools.

C.1.1. Building orientation

If the plot of land to be used for the construction allows the optimum use of the

climatic conditions of the area, the coldest areas of the sports facility (multi-

sports courts) should be located in the northern section of the building and the

warmest (changing rooms, heated swimming pools, ...) in the southern part. To

this respect, the information included in section B.2.1. of this guide should be

taken into account. It is recommendable for the specifications for technical

conditions, which is part of the building project, to include the obligation to justify

the orientation of the same taking into account the specific weather conditions

of the area.

C.1.2. Thermal envelope

Sports facilities in general do not need large glazed surfaces looking out onto

the exterior, which at certain moments can be counterproductive if they are

incorrectly positioned because they can produce dangerous situations caused

by dazzling, shadows or even absentmindedness.

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Therefore, enclosures should be almost completely void of glazed areas and

can be constructed in a uniform way around all the perimeter, including an

optimum thermal insulation in each case depending on the application and

climate conditions of the area. If the installation of a small glazed section in the

closure can be justifiably chosen, so as to provide natural light inside the facility,

the glass to be installed should include at least one or two intermediate air

chambers, depending on the climate and the positioning should also avoid any

type of dazzling effect on the users.

It is always necessary to bear in mind which parts of the building should be

acclimatized and which should not when designing the enclosure of the

building. Therefore, for example, the typical sports pavilion consisting of a multi-

sports court which is not acclimatized and a changing room area which is

heated, should include a simple enclosure in the multi-sports area, but a

correctly insulated enclosure in the changing rooms area. A building designed

exclusively to house a heated swimming pool should feature an enclosure with

highly efficient thermal insulation around the entire perimeter; the following

should also be considered:

- The thermal insulation should be protected against humidity by means of

vapour seals, thin metal plates, plastic sheeting, etc.

- The glazed surfaces should be protected against condensation, for which

double or triple glazing is recommended.

C.1.3. Heating and hot water installations

• Hot water for sanitation. In sports facilities there is usually a considerably high consumption of hot water

for sanitation, used for showers and personal hygiene. This is an application for

which a thermal solar energy installation can provide a good performance, and

therefore, except in justified cases of a high degree of shading, these buildings

should be obliged to install an active solar energy harnessing system to preheat

hot water for sanitation.

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Moreover, the consumption of water should be rationed by means of the

installation of features such as those mentioned in section B.2.3.3.1: nozzle

aerators, water flow interrupters, water-saving taps and showers.

• Central heating.

In terms of central heating it is convenient to distinguish between sports

pavilions and heated swimming pools. In the case of the former, it is

recommendable to install a high efficiency boiler (low temperature or

condensing) or a heat pump, preferably of the geothermal variety, in order to

satisfy not only central heating needs but also to complete the hot water for

sanitation demand during those periods in which the solar contribution is not

sufficient.

In the case of heated swimming pool facilities, the overall thermal necessities,

besides those in common with all other types of pavilions, also include the

following specific needs:

- Heat losses by means of the evaporation of the swimming pool water

- Losses because of the renovation of interior air

- Losses because of the renovation of the swimming pool water

- Losses through convection, conduction and radiation The recommended temperature for public swimming pool water is between 24

ºC and 25 ºC, and in order to avoid a cold sensation, it is necessary to keep the

environmental air between 2 ºC and 3 ºC above this, that is to say between 26

ºC and 28 ºC.

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The relative humidity which is needed to provide a sense of comfort should be

kept between 55% and 70%, preferably at 60%. A low relative humidity (<50%)

would increase losses due to the evaporation of the water and also due to the

energy consumption to dehumidify, and on the other hand, a high degree of

humidity could cause condensation problems on walls and ceilings.

In order to control the humidity of the environment air, it is recommendable to

install a dehumidifying heat pump, on account of its high efficiency. This

device works in a similar way to the scheme represented in the following

diagram:

Installation of a dehumidifying heat pump to acclimatize an indoor swimming pool

The air from the swimming pool which evaporates (hot and humid air) is cooled

in the heat pump evaporator. By means of this cooling process, the excess

humidity in the air is condensed. The cooled, dry air is heated with the heat

pump condenser and returns once again to the swimming pool in the form of

hot, dry air which is needed for renovation.

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The heat surplus in the pump is used to heat the water in the swimming pool.

By using this system, the dehumidification can be carried out without having to

introduce air from the exterior.

As mentioned above, the objective of the dehumidifying heat pump is to control

the humidity in the air, but it can also be used to provide part of the heat which

is needed to heat the water in the swimming pool or the hot water for sanitation

which is needed in the changing rooms. Thermal solar energy harnessing systems are recommendable as a back-up for this system, because they have

an optimum efficiency for heating water at such a low temperature. Finally, as

the solar contribution is unpredictable, in order to guarantee comfortable

conditions, an additional small-size high efficiency boiler should be installed, or

a heat pump instead, preferably of the geothermal variety.

Under no circumstances should outdoor swimming pools be acclimatized, or

those without a certified quality insulated enclosure, unless thermal solar energy

is used exclusively for the purpose.

• Controlling regulation systems.

An appropriate regulation and control system can help to maintain the thermal

demand conditions using an optimum fuel consumption. It is important to

highlight that an increase of 1 ºC in the heating of a pavilion can increase the

consumption of electricity between 5% e un 10%.

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Control panel It is also worth highlighting the importance of maintaining the humidity perfectly

controlled and regulated in the environment of acclimatized swimming pools,

due to the fact that, as mentioned above, a reduction in the humidity can

increase the speed at which the water evaporates and therefore increasing the

energy needed to maintain the required environmental humidity parameters. A

reduction of 5% with regard to the recommended humidity (60%) brings about a

10% increase in evaporation and an increase in the energy needed to

dehumidify.

In order to avoid these problems, it is recommendable to use a regulation

system which can vary the relative humidity requirements in the environment

depending on the exterior temperature, thus avoiding any condensation.

Moreover, there are measures that can be put into practice in order to obtain

considerable savings in energy without the need for large investments, such as

the following:

- Operate using moderate pressures.

- Avoid storing water at excessively high temperatures, even though

these should always be above 60 ºC (so as to avoid the risk of

Legionnaires' disease).

- Install hot water meters.

It is very important to detect leaks in order to eliminate them afterward; to this

respect it is recommendable to install:

- Water flow control divided into areas.

- Installation of manometers for leak detection.

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• Insulations. Heat losses by means of water evaporation in an indoor swimming pool bring

about two negative effects:

- The need to supply heat for the swimming pool water to replace the latent heat of vaporization.

- The need to dehumidify the interior air or supply exterior air to maintain the interior humidity conditions.

In order to avoid these losses, it is recommendable to use a thermal blanket to

cover the surface of the swimming pool whenever it is not being used. On the

one hand the isothermal properties of thermal blankets stop the water

temperature from falling, on the other, they avoid evaporation, therefore

reducing the energy consumption needed to dehumidify the air. The possible

energy saving obtained by using these systems can reach up to 25% of the

energy demand.

Photo of a thermal blanket The advantages of installing this type of equipment are the following:

- A reduction of energy costs needed to dehumidify at night.

- In those cases where the dehumidification systems are switched off at night, the measures avoid the resulting deterioration of the pavilion walls due to condensation.

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The disadvantages of these systems are:

- The need to reserve an additional area to house the thermal blanket

when it is not being used. It is worth noting that there are brackets

available to fix the blanket framing to the structure of the building, thus

minimizing any storage problems.

- The daily installation and storage of the blanket, which can be made

easier by means of a motor-driven blanket.

With regard to the piping and other heat transport elements, it is worth

remembering that they should be properly insulated.

C.1.4. Refrigeration installations

Generally, the air in sports pavilions is not refrigerated except with the purpose

of dehumidification.

In acclimatized swimming pools the environment air is cooled in order to make

the humidity condensate. Once it is dry, it is heated again up to the required

temperature, using the same energy which was previously claimed from it in

order to cool it. Furthermore, part of the energy from the condensation of the

humidity is left over, and this is normally used to heat the water in the swimming

pool. The less energy necessary to reheat the cooled air, the more energy will

be available for other uses, such as heating the water in the swimming pool or

hot water for sanitation.

C.1.5. Ventilation

In all sports pavilions, whether they include an indoor swimming pool or not, it is

necessary to ventilate the air inside the premises. In the case of non-

acclimatized facilities, this renovation can be carried out directly by means of

infiltrations and by introducing air through the main entrance.

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In the case of acclimatized premises in which the humidity is controlled, such as

swimming pools, the renovation of the air should be regulated and regeneration

equipment should be installed, in order to make the most of the outgoing air to

condition the incoming air. Furthermore, it is convenient to:

- Use modulating air renovation systems depending on occupation. - Avoid infiltrations. - Not to excessively overdimension the hygienic renovation of the air.

C.1.6. Artificial illumination installations

The electricity consumption of a sports pavilion is fundamentally due to the

illumination and acclimatization equipment.

Municipal sports tracks Municipal multisports pavilion

The main objective when illuminating any sports area, whether it is indoor or

outdoor, is to offer the users an appropriate environment to practice sporting

activities. Therefore, the type of illumination will be different depending on the

activity which is going to be carried out in each case. Consequently, for

example, the players and referees should be able to see clearly what is taking

place on the playing area, whilst the spectators should be able to see the

activity without having to make a great effort and in a pleasant visual

environment. In the following table we have detailed recommended illumination

levels, depending of the type of sport which is going to be practiced in each

case.

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SPORT Horizontal illumination (lux)

Leisure Training Competition Indoor athletics 200 300 500

Outdoor athletics 100 200 400

Indoor

basketball/handball/volleyball 300 400 600

Outdoor basketball/handball 100 200 500

Indoor football 300 400 600

Outdoor football 100 200 500

Gymnastics/judo 300 400 600

Outdoor swimming 100 200 400

Indoor swimming 200 300 500

It would be necessary to split the power in order to adapt the illumination level

to the utilization level, thus limiting it to the values recommended above. The

most efficient equipment should be installed for each case, always maintaining

the required levels of illumination. In general, for small outdoor courts (not

taking into account televised events), the most profitable installation is the high

pressure sodium vapour variety, whereas those used for indoor facilities are

fluorescent and halogen lighting, for low (≤ 5 m) and high ceiling heights

respectively.

• Energy saving measures for transformers and motors

As mentioned above, the majority of the electricity consumed in a multisports

pavilion is due to the illumination and acclimatization equipment. The

performance of a transformer used to supply the electric energy necessary is at

an optimum level whenever it operates over 50% of the load, and also

increasing when the secondary power factor grows. In order to reduce losses in

transformers it is necessary to:

200

- Choose the transformer to work at 70-80% of its capacity.

- Compensate the reactive energy consumption of the transformer itself

by using fixed condensers on the secondary winding.

- Disconnect inoperative equipment, to avoid iron losses.

In the case of motors, a similar situation occurs, given that the efficiency is at a

maximum at 75-85% of the load. It is very important to choose motors in relation

to their loads.

SUMMARY OF SECTION C.1

• It should be compulsory for the building project contract specifications

to include a summary of the construction site’s climatic conditions in the

building project itself: temperatures, insolation, humidity and

predominant wind directions.

• The building project contract specifications should also justify the

orientation, distribution of the rooms and the building’s envelope.

• The building should avoid unnecessarily large glazed surfaces.

• The consumption of hot water for sanitation during the summer months

should be satisfied exclusively by means of thermal solar energy.

Measures encouraging the rational use of water should also be used.

• In those facilities with acclimatized swimming pools it is essential for the

temperature of the air to be 2 or 3 degrees above the temperature of the

water. Otherwise the environment will feel cold and thus the

temperature of the water will usually be increased, and consequently

the consumption of energy. Therefore, no expense should be spared

when installing equipment to measure, regulate and control the

temperature of the environment.

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• The control of the humidity in acclimatized swimming pools should

preferably be carried out by means of a dehumidifying heat pump. The

surplus heat from this process can be used to heat hot water for

sanitation or the water in the swimming pool itself.

• As a back-up system for the heat pump, solar panels should be used as

well as a high efficiency boiler or a geothermal heat pump.

• The installation of a thermal blanket is obligatory in acclimatized

swimming pools in order to be used on the surface of the water

whenever the swimming pool is closed.

• In facilities which are not acclimatized, natural ventilation is appropriate.

In acclimatized swimming pools the artificial ventilation systems which

are installed should be adjustable depending on the level of occupation.

• The illumination equipment should be appropriately divided into

sections in order to adapt it to the recommended illumination level of the

activity being carried out.

• In general, for small outdoor courts (not taking into account televised

events), the most profitable installation is the high pressure sodium

vapour variety, whereas those used for indoor facilities are fluorescent

and halogen lighting, for low (≤ 5 m) and high ceiling heights

respectively.

C.2. School complexes School complexes include the set of premises dedicated to teaching within a

council and they make up for approximately 12% of the council’s energy

consumption.

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C.2.1. Building orientation

School complexes are generally built on spacious plots where playing grounds

are usually available for the school children. This means that in the majority of

cases there will be a certain degree of freedom in so far as the orientation of the

building which will make it easier to exploit the climatic conditions of the area as

much as possible. For this reason, it is especially important to take into account

the information in section B.2.1.1 of this guide and it is recommendable for the

specifications for technical conditions, which are part of the building project, to

include the obligation to justify the orientation of the same taking into account

the specific weather conditions of the area.

Other aspects should also be provided for, such as the possibility of planting

deciduous trees by the southern façade (to protect against the heat in summer

and to let light through in winter) and evergreen leaf trees by the northern

façade (to protect against the cold in winter), which will help to increase the

level of comfort inside the building and to reduce the energy expense.

203

C.2.2. Thermal envelope The thermal envelope used in school complexes will be strongly conditioned by

the need for natural light, which is especially important in this type of building for

psychological reasons. This means that special care has to be taken with

regard to the thermal characteristics of the windows, demanding a minimum of

at least one or two air chambers between window panes (depending on the

area). For more information, please turn to section B.2.2.


• Central heating. The consumption for central heating is the main consumption of energy in a

school building. A priori, one of the recommended solutions for the generation

of necessary heat will be the use of either a centralized high efficiency boiler or

a geothermal heat pump. In large school complexes, or in very cold climates, it

may be interesting to study the viability of installing a cogeneration plant, this

could be profitable mainly in facilities where there is a double teaching shift,

given that generally a single teaching shift does not include enough annual

operating hours in order to get a return on the installation costs.

Using systems based on electric heating can only be considered for those

premises which are located far from heat distribution lines and which are only

used occasionally.

• Insulations.

Once the necessary heat has been generated, it must be transported to the

area where it is to be used, whilst guaranteeing an appropriate insulation of the

conduits. To this respect, it is worth remembering that the lower the temperature

of the heat carrying fluid, the more comfortable and efficient the heating system.

204


Finally, it is of the utmost importance to regulate the final heat exchange units

correctly. A common situation arises whereby once the central heating has

been switched on, school children open windows in order to compensate for

any excess heating.

So as to avoid this, it is recommendable to install regulating devices which can

cut the heat flow into a room whenever a window is open. Furthermore, a non-

adjustable thermostat should be installed in each class room, enabling the

heating to be turned on or off automatically depending on whether the

temperature increases or decreases with respect to a specific value.

It is not recommendable to install individual thermostats on each radiator,

because whenever they are closed due to an excess of heat, none of the school

children will remember to open them again so that the classroom can be

properly heated for the next day. Below we have detailed reference

temperatures for different types of work spaces.

AREA TEMPERATURE (ºC)

Reception 18

Administration 20

Secretary’s Office 20

Class rooms 18-20

Libraries 21

Offices 20

Assembly hall 20

Meeting rooms 20

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• Hot water for sanitation.

In those school complexes where there is a demand for hot water for sanitation,

for example in sports pavilion shower facilities, it is convenient to install thermal

solar panels in order to preheat it. Furthermore, any taps and showers should

include nozzle aerators and timers. For more information, please turn to section

B.2.3.3

C.2.4. Refrigeration installations In general, due to the fact that during the warmest moths of the year is when

school holidays are planned, it should not be necessary to install air

conditioning equipment except in those rooms where computer equipment is

used. To this respect, it is worth highlighting that this type of activity is

increasingly popular, therefore when designing new buildings, one should

consider the possibility that in the future it may be necessary to acclimatize

most of the rooms of the building, especially those in warmer areas.

Consequently, in these cases bidders should be obliged to provide the building

with a minimum preinstallation. Only when the acclimatization of one or two

computer rooms is planned, should independent units de installed, and these

should necessarily include the best energy labelling available.

The design of the building should allow for these rooms to be located in the

northern area of the building, and for the acclimatization system air intake also

to face North. In those cases where the climate conditions and/or the use of the

building in summer bring about the need to acclimatize the majority of the

building, centralized cold installations should be chosen, given that they are

more efficient when running at partial loads and they are more easily managed

(high efficiency measures can be put into practice, such as freecooling,

whereby the temperature of the exterior air is partly used as long as it is lower

than the temperature of the acclimatization system’s return flow (approx. 25

ºC)).

206

In this type of situation (the acclimatization of the entire building) it is convenient

to carry out the heating of the premises by making the most of the final cold

exchange units themselves, for example by using fan coils. When the heating

installation is centralized, it is especially important to make sure that the

conduits are properly insulated.

C.2.5. Ventilation The ventilation of school premises is normally carried out directly by opening

windows. If it is necessary to include rooms which do not have natural

ventilation, such as computer rooms, or if there are special reasons for an

artificial ventilation system to be installed in a large part of the building,

regeneration systems should be installed, because they allow the outgoing hot

or cold air to be reused in order to condition the air which is needed for

renovation.

Furthermore, and given that the occupation of the class rooms is rather

variable, it is convenient for the equipment controlling the renovation to

regulate the air depending on the level of occupation. In those rooms with

forced ventilation, there should be no openable windows.

C.2.6. Artificial illumination installations The special characteristics of the activities which are carried out in school

complexes need an in depth study into the illumination of these premises. In

general, the following can be differentiated, among others:

- Classrooms (theory)

- Classrooms (practical): (laboratories, design, computing, etc.)

- Teachers’ lounge

- Assembly hall

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- Library

- Gymnasium

- Administration offices

- Offices

- Halls, corridors and staircases

- Showers and toilets

As a general guideline, in classrooms used for theory and in common areas, it

is recommendable to install fluorescent lamps with electronic ballasts which

can be adjusted depending on the amount of natural light, at least in those

sources of light which are close to windows.

In areas used for indoor sports activities, metal halide or high pressure sodium

vapour discharge lamps should be used. If the activities are outside, high

pressure sodium lamps should be installed.

When selecting the appropriate type of luminaire, lamp or auxiliary equipment,

first of all it is necessary to determine the type of room being studied, keeping in

mind the activity which is going to be carried out in it. The recommended

illumination parameters for different types of premises in a school complex can

be checked in section A.2.3 of this guide.

In terms of optimizing the exploitation of the energy being consumed for

illumination, the building project should allow for the use of paints and colours

on walls, ceilings and floors which favour energy saving in so far as illumination

(light colours).


An optimum management of the illumination is essential in order to obtain good

energy efficiency results. Below, we have described some illumination control

strategies:

208

- Programming: the illumination and distribution levels can be

programmed automatically when the daily routine of activities is known.

- Illuminance control: systems are normally designed with illumination

levels 30-50% above those necessary, whereby it is important to know

what these levels are in order to maintain a correct illuminance for each

area.

- Power optimization: a considerable saving in energy can be obtained if

the illumination levels are reduced during certain periods of time in non-

essential areas. As a result, it is recommendable to install time control

systems, which turn lights off depending on a specified time of the day.

- Using presence detectors: with regard to the aforementioned point,

there are devices available related to the level of occupation which use

presence detectors to turn on the light whenever they detect someone

and to turn it off when no presence is detected after a certain time. They

are appropriate for areas which are not constantly occupied (corridors,

storeroom, toilets, ...).

- Daylight control systems: this type of control is based on a series of

photocells which regulate the power of the lamps depending on the

natural light which is available.

- Illumination management systems: in multi-purpose buildings it would

be interesting to analyse the possibility of including an illumination

management system which includes an overall centralized control, in

order to be able to reduce the energy consumption a further 15% with

respect to the previous systems.

209








• Measures encouraging the rational use of water should also be installed

on taps and toilets.

• In terms of central heating, it is recommendable to install either a high

efficiency boiler (low temperature or condensing) or geothermal heat

pumps.

• No expense should be spared when installing equipment to measure,

regulate and control the temperature of the environment. Nevertheless,

it is not recommendable to install individual thermostats on each

radiator, because whenever they are closed due to an excess of heat,

none of the school children will remember to open them again so that

the class room can be properly heated for the next day.

• The design of the building should allow for computer rooms to be

located in the northern area of the building, and also guarantee that the

acclimatization system air intake faces a shaded area.


sections and automated to avoid consumption in empty rooms.

• In general, it is recommendable to use fluorescent lamps with electronic

ballasts.

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C.3. OFFICE BUILDINGS

C.3.1. Building orientation Office buildings are generally constructed on sites which do not allow their

orientation to be adjusted, therefore the interior design as well as the

morphology and material of the façades, will have to be adapted to the climatic

characteristics and orientation imposed by the sun (turn to section B.2.1).

In those cases where there is a certain degree of freedom with respect to the

arrangement and orientation of the buildings, the most compact design possible

is recommended, this means with the highest possible volume/surface ration in

relation to the natural light necessities, which will in turn reduce the

acclimatization consumption.

C.3.2. Thermal envelope The envelope of those buildings which are to be used as offices, usually

requires a considerable glazed surface, in order to make the most of the

available natural light and for psychological reasons. Notwithstanding, it is often

the case that curtain walling or any other type of excessively glazed enclosure

are overused. As a result, the positive psychological effects obtained from the

use of natural light partly disappear due to the low thermal comfort level.

The situation is as follows: during winter months, in the early morning there is a

strong cold sensation due to the inappropriateness of the thermal enclosure (a

high number of losses because of conduction and radiation). Consequently,

there is a very high thermal demand for central heating during the first few

hours of the day.

211

Closer to midday, as the sun rises, the thermal sensation slowly changes due to

solar radiation and to the heat given off by the office equipment, possibly

becoming too warm and creating a demand for refrigeration.

All of this means that it is incredibly complicated to regulate and control the

environmental conditions, that the thermal comfort is low due to excessive

temperature gradients and that the energy consumption is high.

During the summer months the situation is similar, an unjustified cold sensation

during the first few hours of the morning which quickly gives way to excessive

heat during the rest of the day.

When designing the envelope of an office building, the aforementioned should

be taken into account, thus including sufficient glazed surfaces but avoiding the temptation to install completely glazed façades.

Furthermore, because most office buildings normally include central heating, to

say the least, all glazed surfaces should have one or two air chambers between

window panes depending on the climatic conditions of the area.

Similarly, high ceilings should be avoided in office areas, due to the fact that

these increase the volume to be acclimatized, thus reducing the response

capacity of the equipment and making it difficult for the system to be finely

tuned, regulated and controlled.

Wide openings should also be avoided when communicating adjacent floors, because this causes the stratification of the air temperature, increasing

the environment temperature in higher areas and reducing it lower in the

building.

212


• Central heating. An important detail to be taken into account when designing the central heating

installation for an office building, is that during the lifetime of the construction it

is quite likely that the interior distribution will be changed, therefore priority

should be given to a distribution which is planned to be easily adapted to any

possible changes.

In so far as central heating, a priori, one of the recommendable solutions to

generate the heat needed would be the installation of either a high efficiency

centralized boiler or a heat pump, preferably of the geothermal variety. In large

office centres, or in very cold climates, it may be interesting to study the viability

of installing a cogeneration plant, this could be profitable mainly in facilities

where there is a double work shift, given that generally a single work shift does

not include enough annual operating hours in order to get a return on the

installation costs.

Using systems based on electric heating can only be considered for those

premises which are located far from heat distribution lines and which are only

used occasionally.

• Insulations.

Once the necessary heat has been generated, it must be transported to the

area where it is to be used, whilst guaranteeing an appropriate insulation of the

conduits.

To this respect, it is worth remembering that the lower the temperature of the

heat carrying fluid, the more comfortable and efficient the heating system, even

though this may imply the installation of larger exchange surfaces.

213

All of the hot water piping should be conveniently insulated along the entire

length of the pipes, including any valves, connectors, clamps, joints and

equipment..., so as to avoid any heat loss from them.

The characteristics of the insulating materials, as well as the thickness of these,

will mainly depend on the temperature of the water and on the diameter of the

tubing.

• Regulation systems.

Finally, it is especially important to regulate the final heat exchange units

correctly. As in the case of school complexes, it is common that once the

central heating has been switched on, windows are opened in order to

compensate for any excess heating.

So as to avoid this, in buildings which include forced ventilation windows should

not be openable and it is recommendable to install regulating devices which can

cut the heat flow into a room whenever a window is open in those buildings with

natural ventilation.

Furthermore, an adjustable thermostat should be installed on each radiator,

given that the cold-hot sensation is highly subjective and this means that each

worker is able to adjust the comfort level personally. Workers are supposedly

responsible when using this thermostat. Nevertheless, an automatic thermostat

should be installed in each office work area in order to cut or start the heating if

the temperature is too far out of the predetermined range.

214

• Hot water for sanitation.

In an office building it is not common for there to be a demand for hot water for

sanitation, except in those cases where there are additional services such as

cafeterias.

Notwithstanding, the consumption of water should be rationed by means of the

installation of features such as those mentioned in section B.2.3.3.1: nozzle

aerators, water flow interrupters, water-saving taps and showers.

C.3.4. Refrigeration installations As in the aforementioned case dealing with central heating, an important detail

to be taken into account when designing the air conditioning installation for an

office building, is that during the lifetime of the construction it is quite likely that

the interior distribution will be changed, therefore priority should be given to a

distribution which is planned to be easily adapted to any possible changes.

The installation should be divided into several areas (at least two per floor:

North and South) depending on the specific legislation of each country and on

the number of rooms dedicated to different uses on each floor.

Independent units should be installed only when the acclimatization of a small

area of the building is planned, due to the foreseeable internal load, and these

should necessarily include the best energy labelling available. As far as

possible, the design of the building should allow for this area to be located in the

northern area of the building, and for the acclimatization system air intake also

to face North.

In those cases where the climate conditions and/or the use of the building mean

that it is recommendable to acclimatize the majority of the building, centralized

cold installations should be chosen, given that they are more efficient when

running at partial loads and they are more easily managed (high efficiency

215

measures can be put into practice, such as freecooling, whereby the

temperature of the exterior air is partly used as long as it is lower than the

temperature of the acclimatization system’s return flow (approx. 25 ºC).

In this last case, it would be convenient to heat the premises by making use of

the same cold application terminal system, for example, by distributing hot

and/or cold water depending on the demand and applying it using fan coils.

In these cases, it is especially important to make sure that the conduits are properly insulated as well as any accessories along their entire length.

C.3.5. Ventilation

The ventilation of small office buildings is normally carried out directly by

opening windows. In the case of large office complexes or if it is necessary to

include rooms which do not have natural ventilation, such as computation

centres, conference rooms, or if there are special reasons for an artificial

ventilation system to be installed in a large part of the building, regeneration systems should be installed, because they allow the outgoing hot or cold air to

be reused in order to condition the air which is needed for renovation.

Furthermore, it is convenient for the equipment controlling the renovation of air

to regulate it depending on the level of occupation, always taking great care

to respect the minimum hygiene standards without moving exaggerated

volumes of air.

Finally, in those rooms with forced ventilation, there should be no openable

windows.

216

C.3.6. Artificial illumination installations

The specific characteristics of the activities which are carried out in offices need

an in depth study into the illumination of these premises. In general, the

following can be differentiated, among others:

- Meeting rooms

- Graphic design rooms

- Conference rooms

- Library

- Administration offices

- Offices

- Halls, corridors and staircases

In general terms, it is recommendable to install fluorescent lamps using electronic ballasts designed to provide the maximum quality of light for work

areas. The equipment should be fitted with devices to enable them to regulate

the quantity of illumination, at least those located near windows.

The recommended parameters for different types of rooms that are to be found

in office buildings have been included in section A.2.3.

For an optimum exploitation of the illumination installation, the building project

should allow for the use of paints and colours on walls, ceilings and floors which

favour energy saving in so far as illumination.

• Regulation systems.

An optimum management of the illumination is essential in order to obtain good

energy efficiency results.

Below, we have described some illumination control strategies:

217

- Programming: the illumination and distribution levels can be

programmed automatically when the daily routine of activities is known.

- Illuminance control: systems are normally designed with illumination

levels 30-50% above those necessary, whereby it is important to know

what these levels are in order to maintain a correct illuminance for each

area.

- Using natural light: carrying out a correct adjustment of the illumination

levels adapted to the natural light which is available can bring about a

considerable energy saving. This equipment uses photocells to regulate

the power of lamps depending on the quantity of natural light.

- Power optimization: a considerable saving in energy can be obtained if

the illumination levels are reduced during certain periods of time in non-

essential areas. As a result, it is recommendable to install time control

systems, which turn lights off depending on a specified time of the day

- Using presence detectors: with regard to the aforementioned point,

there are devices available related to the level of occupation which use

presence detectors to turn on the light whenever they detect someone

and to turn it off when no presence is detected after a certain time. They

are appropriate for areas which are not constantly occupied (corridors,

storeroom, toilets, ...).

- Illumination management systems: in multi-purpose buildings it would

be interesting to analyse the possibility of including an illumination

management system which includes an overall centralized control, in

order to be able to reduce the energy consumption a further 15% with

respect to the previous systems.

218








• The building should avoid excessively large glazed surfaces.

• The central heating and refrigeration systems should allow for a certain

amount of flexibility in terms of the interior layout, in order to adapt to

possible changes.

• The offices should not have excessively high ceilings, nor should

several floors be communicated by means of wide openings, because

this increases the consumption for acclimatization and makes it difficult

to regulate the environment.

• In terms of central heating, it is recommendable to install either a high

efficiency boiler (low temperature or condensing) or geothermal heat

pumps.

• No expense should be spared when installing equipment to measure,

regulate and control the temperature of the environment.

• Measures encouraging the rational use of water should also be installed

on taps and toilets.


sections and automated to avoid consumption in empty rooms.

• In general, it is recommendable to use fluorescent lamps with electronic

ballasts.

219

Anexo Appendix: TYPES OF LAMPS

220

Lamps and auxiliary equipment

Any lamp being used for public illumination should meet a series of

characteristics which are determined by the illuminance parameters. Among the

most important of these, it is worth highlighting luminous efficacy and the

working life of the lamp.

Choosing any specific type of lamp will depend on the application which is

necessary in each case, of the characteristics they feature and of the monetary

factors, such as the price of the lamp, its installation cost, replacement and

operating costs.

Therefore, for example, a high luminous efficacy diminishes not only installation

costs (installed capacity of power) but also operating costs (energy consumed),

and similarly, a longer working lamp life diminishes the replacement costs of the

same.

Other important characteristics, in so far as defining the type of lamp for a

specific illumination, are temperature and colour rendering.

Below we have detailed and analysed each of the main types of lamps.

Types of lamps:

Incandescent lamps:

- Conventional

- Halogen

Mercury vapour discharge lamps (m.v.):

- Fluorescent (low pressure m.v.)

- High pressure (colour corrected)

- Blended lamps (incandescent and high pressure m.v.)

- Metal halide

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Sodium vapour discharge lamps:

- Low pressure

- High pressure

Induction lamps:

- Electrodeless fluorescent

- Low pressure

Light emitting diodes

1. Incandescent lamps

The operation of this type of lamp is based on emitting light as a consequence

of the heat produced when an electric current passes through a wire in the

shape of a filament. This wire is enclosed inside a bulb, which is filled by a gas.

There are different types of incandescent lamps available depending on the

type of screw base or contact cap, filament and bulb. This type of lamp can be

connected directly to the mains supply, and therefore they do not need any type

of auxiliary equipment. They are normally only used for interior illumination.

Conventional incandescent lamps: This is the oldest and most

commonly used commercially available lamp. The working principle is

based on heating a filament using electricity until it reaches a high

temperature and thus emits visible radiation. These lamps emit about

20% of the energy they consume in the form of light and the remaining

80% is lost in the form of heat.

222

Several types are available depending on the shape of the bulb:

standard, candle, round, blown glass reflector and pressed glass

reflector.

CONVENTIONAL INCANDESCENT LAMPS


Low cost (1-6 €/unit).

Excellent colour rendering (IRC – Ra: 100)

Vast variety of shapes, sizes, colours and voltages.

Low luminous depreciation.

Short duration (working life of 1,000-3,000 hours).

Low performance (8 - 20 lum/W).

Halogen lamps: this is a variation of the incandescent lamp in which a

halogen gas is added (iodine, chlorine, bromine) to the inert gas inside

the bulb. Furthermore, the glass used to make the bulb is replaced by a

quartz glass due to the high temperatures the lamp can reach.

HALOGEN LAMPS


Low cost (4-25 €/unit).

Whiter and more brilliant light than standard incandescent lamps.

Excellent colour rendering (IRC – Ra: 100)

Constant luminous flux.

Small size.

Several models.

Short duration (2,000 – 5,000 hours) but longer than standard incandescent lamps.

Low efficiency (13 - 25 lum/W) (higher than standard incandescent lamps).

When the temperature of the filament increases, the working life decreases.

The low voltage variety need a transformer (additional consumption).

223

2. Mercury vapour discharge lamps These lamps consist of a tube which contains mercury vapour. The light

(ultraviolet) is produced when the mercury vapour is excited by electric

discharges between two electrodes. Included among this type of lamp, are the

following:

Fluorescent lamps: low pressure mercury vapour discharge lamp, in

which visible light is produced mainly by means of fluorescent powders

which line the inside of the tube being activated by the ultraviolet energy

from the discharge in the mercury. They are used exclusively for interior

illumination.

The colour rendering of these lamps varies from moderate to excellent

depending on the fluorescent substances which are used. Similarly, the

appearance and temperature of the colour vary depending on the specific

characteristics of each lamp.

Colour appearance

Colour T (K)

Warm white 3,000

White 3,500

Natural 4,000

Cold white 4,200

Daylight 6,500

224

FLUORESCENT LAMPS


High efficiency (40 – 100 lum/W).

Low – average price (3-45 €/unit).

Good colour rendering (Ra: 60 – 90).

Very long duration (working life: 6,000 – 79,000 hours).

Slight luminous depreciation.

Several sizes.

Variety of models.

They require a starting element and current limiting (starter and ballast) which implies a consumption of about 10% of the power of the lamp.

The working life of the lamp depends on the type of ballast and the number of ignition/shut down cycles (with an electronic ballast and preheating the lamplife is 50% longer than with an electromagnetic ballast).

They contain mercury (any faulty lamps should be deposited wherever replacements are bought).

Compact fluorescent lamps:

This is a variation of fluorescent tubes which were adapted

to substitute incandescent lamps without having to carry out

any type of installation. It is a fluorescent tube which

incorporates a ballast.

COMPACT FLUORESCENT LAMPS


Long duration (working life: 3,000 – 15,000 hours).

High efficiency (65 – 90 lum/W).

Low consumption. (Energy saving of up to 80% with respect to an incandescent lamp).

User friendly.

Good colour rendering (> 80).

Price (10 – 36 €/unit). Even so, the return with respect to an incandescent lamp is less than one year.

They generally do not admit luminous intensity regulators (only some models can be regulated).

225

High pressure mercury vapour lamp: the discharge is produced inside

a quartz tube which contains a small quantity of mercury and is filled with

inert gas, generally argon, so as to help ignition. The internal surface of

the bulb which encases the tube is lined with a fluorescent powder in

order to increase the emission of light in the visible range.

HIGH PRESSURE MERCURY VAPOUR LAMPS


Long working life (8,000 to 16,000 hours).

Average luminous efficacy (35 – 60 lum/W).

Low – average price (9-30 €/unit).

They require a starting element and current limiting (starter and ballast) which implies a consumption of about 10% of the power of the lamp.

They need to cool down between ignitions (once they have been turned off they cannot re-ignite until they are cold).

Average colour rendering (50-60).

They contain mercury (any faulty lamps should be deposited wherever replacements are bought).

Blended lamps: their objective is to eliminate the blueish light emitted by

mercury vapour lamps, so inside the same discharge tube there is an

incandescent filament of tungsten. As a result, it becomes a mixture

between a mercury and an incandescent lamp.

226

This type of lamp can be connected directly to the mains supply without

the need for a reactant, because the filament, apart from being a source

of light, also acts as a stabilizing resistance for the mercury vapour

discharge. They tend to be used as replacements for incandescent

lamps.

BLENDED LAMPS


They do not require auxiliary equipment.

Average working life

(5,000 – 7,000 hours).

They require cooling periods between ignitions.

Sensitive to power surges.

Average colour rendering

(50 - 65).

Low efficiency

(20 – 26 lum/W).

They contain mercury.

227

Metal halide lamps: these lamps are similar to the high pressure

mercury vapour variety, but they also contain “rare earth halides”, the

element which generates the light (the mercury only acts as a regulator).

METAL HALIDE LAMPS


High luminous efficacy (70 – 105 lum/W).

Very good colour rendering

(60 – 95).

Long working life

(10,000 – 12,000 hours).

High price

(60 – 150 euros/unit).

They require auxiliary equipment (increasing consumption by up to 15%).

The working position is generally restricted (only some types are universal).

They require cooling periods between ignitions.

228

3. Sodium vapour discharge lamps The visible light is produced using a discharge in the sodium vapour. They are

classified into high and low pressure lamps.

Low pressure sodium vapour: The visible light is produced using a

discharge in a low pressure sodium atmosphere.

This type of lamp emits an orange-yellowish colour when it is connected

because there is not enough heat in the tube to vaporize the sodium.

When the ignition becomes stabilized, the luminous flux is

monochromatic (yellow), and this is why the colour rendering is so low.

But, it is the most efficient of the discharge lamp variety (twice as much

as a low pressure mercury vapour lamp -fluorescents-).

They are ideal to supply illumination when the predominant purpose is

citizen surveillance and when colour rendering is not important:

illumination of cross-country thoroughfares (motorways,...), tunnels, rural

areas and any areas which require security lighting in general.

229

LOW PRESSURE SODIUM VAPOUR LAMPS ADVANTAGES DISADVANTAGES

Very high luminous efficacy (the highest of all type of lamps) 100 – 200 lum/W.

Long working life: 12,000 hours.

Short re-ignition time: <1 minute.

They permit visibility even in foggy conditions.

Moderate price (30 – 100 euros/unit).

High consumption of the auxiliary equipment (increasing consumption by up to 50%).

The working position is restricted.

Null colour rendering (IRC=0).

Large size.

High pressure sodium vapour: light

is produced using a discharge inside

an atmosphere of high pressure

sodium vapour. This type of lamp has

a high luminous efficacy, but their

colour rendering is low (IRC: 25 – 65).

High pressure sodium vapour lamps

seem to produce a yellowish colour.

There is a variety of these lamps,

known as “white sodium”, which emits

an apparently warm white colour, with

a colour rendering index of around 80,

consequently improving the chromatic

characteristics of high pressure

sodium vapour lamps, even though

the energy efficiency is lower.

230

The main use for this type of lamp is in facilities which have a high level of

motor vehicle traffic, for illuminating old towns and non-commercial streets, for

the exterior lighting of buildings and the interior illumination of sports facilities.

HIGH PRESSURE SODIUM VAPOUR LAMPS


High luminous efficacy (70-150 lum/W).

Very long working life (10,000 – 24,000 hours).

Average colour rendering (IRC from 25 to 65).

They accept any working position.

They require auxiliary equipment (increasing consumption by up to 15%).

They require cooling periods between ignitions (1-15 minutes).

4. Induction lamps The working principle of induction lamps is based on low pressure gas

discharge systems, but they introduce a totally different process due to the fact

that they do not use electrodes to produce the discharge, like the

aforementioned cases, and this means that the working life of the lamp can be

increased and still maintain a very high luminous efficacy. Within this group of

lamps there are two different types:

- High power electrodeless fluorescent lamps.

- Low pressure gas discharge induction lamp.

High power electrodeless fluorescent lamps: this type of lamp is

made up of a sealed fluorescent tube in the shape of a ring, in which a

discharge is produced using an external magnetic field.

231

This magnetic field is produced in two ferrite rings, and furthermore,

external electronic control equipment is necessary for the lamp to

function correctly.

Anel de ferrita

Bobina

Corrente eléctrica

Recubremento fluorescente

Lámpada fluorescente de alta potencia sen electrodos

Anel de ferritaTubo fluorescente

The main characteristics of this system are the extremely long working

life besides good luminous efficacy. Similarly, this type of lamp can

instantly supply visually comfortable light without any oscillations. Due to

the long duration of these lamps, they are appropriate for areas which

are difficult to access and where illumination is needed during long

periods of operating time.

HIGH POWER ELECTRODELESS FLUORESCENT LAMPS ADVANTAGES DISADVANTAGES

High luminous efficacy

(80 lum/W).

Very long working life (60,000 hours).

Good colour rendering

(IRC from 80 to 89).

Comfortable light without oscillations.

Immediate ignition without flickering.

They require electronic control equipment (reducing overall efficiency to 75 lum/W).

Very high price.

Total cost without luminaire: 515 euros (the lamp costs 315 euros and the ballast 200 euros).

232

Low pressure gas discharge induction lamp: the lamp is made up of

a recipient where we can find the low pressure gas and a power adaptor

which creates an electromagnetic field which produces the gas

discharge.

Furthermore, the system includes a high frequency generator which

controls the ignition and maintains the discharge.

Lámpada de descarga de gas a baixa presión por inducción

Ampola

Adaptadorde potencia

Casquillo

Corrente eléctrica

Recubrementofluorescente

Gas de mercurio

Campoelectrmagnético

XERADOR DEALTA FRECUENCIA

This type of lamp are especially recommended to reduce maintenance costs in

areas where illumination is needed during long periods of operating time and

where it may prove difficult to replace them (tunnels, areas with difficult access,

etc.).

233

LOW PRESSURE GAS DISCHARGE INDUCTION LAMPS


High luminous efficacy (65-75 lum/W).

Very long working life (60,000 hours).

Good colour rendering (IRC from 80 to 89).

Comfortable light without oscillations and immediate ignition.

Universal working position.

Adequate system for explosion resistant luminaires.

They need two auxiliary elements: high frequency generator and antenna.

Very high price (total cost without luminaire: 460 euros).

5. Light emitting diodes (LED)

An LED, the English acronym for Light-Emitting Diode, is a semiconductor

device which emits polychromatic light, that is to say, with different

wavelengths, when it is directly polarized and the electric current passes

through it. The colour depends on the semiconductor material used to

manufacture the diode, and this can vary from ultraviolet, passing through the

visible light range, up to infrared.

The use of LED lamps in the field of illumination is quite likely to increase in the

future, due to their superior characteristics to incandescent lamps (longer

working life, more resistant and less energy dissipation, besides the higher

luminous efficacy to produce coloured light).

234

LIGHT EMITTING DIODES ADVANTAGES DISADVANTAGES

Superior luminous efficacy to incandescent lamps to produce colours.

Very long working life (up to 100,000 hours).

Good colour rendering (IRC from 75 to 80).

Comfortable light without oscillations.

Immediate ignition without flickering.

Low luminous efficacy (10-20 lum/W).

Very high price (20-40 euros/W).

They require auxiliary equipment (power supply source).

Glossary of building envelope technical terms:

Thermal capacity.- this can be defined as the capacity of different materials to

store heat. It is expressed in specific values, in both units of mass and volume:

KJ/m3 ºC or KJ/kg ºC.

The capacity of different common materials have been detailed in the following

table:

Material KJ/m3 KJ/kg ºC Water 4160 4.19 Steel 3960 1.89 Stone 2415 0.88 Concrete 2080 0.88 Brick 1680 0.84 Wood 940 0.84 Rock wool 27 0.50

Condensation.- the physical process which consists of a substance changing

from a gaseous form to a liquid form.

Condensation in building enclosures is produced whenever the hot interior air

flowing through the enclosure reaches the colder exterior layers.

235

Types of condensation:

Superficial: these are produced in the interior surfaces of the building.

Interstitial: these are produced in the various layers or sections which

make up the enclosure.

Thermal conductivity (�).- the quantity of heat that can

be transmitted through a surface of 1m2 in a flat body

with parallel sides, separated by 1m, when there is a

temperature difference of 1ºC between both sides during

1 hour.

Windows. Elements

Two jambs or vertical pieces which

frame its sides; a sill which forms the

horizontal bottom piece and a lintel

which forms the top section.

The lock consists of a frame or sash

(made of wood or metal) to which the

glass panes are attached by means

of fixtures.

Diagram: window with double glazing and air chamber

236

Windows. Typologies → Openable

• Sliding.- the panes slide along horizontal rails.

• Guillotine.- the panes slide using vertical guides.

• Awning.- they rotate around a horizontal axis. They can be:

o Outward swinging.

o Inward swinging.

• Casement.- rotating around a vertical axis.

• Turn-and-tilt.- they include hinges that allow the window to either tilt

inwards at the top or to function as a casement window.

→ Unopenable/fixed

Air flow.- the flow of air through enclosures can occur in three main ways:

Through cracks and lineal openings which appear due to faults in the

sealings between elements.

By means of diffusion, due to the air permeability of the materials.

“Channelled” air flow. This is probably the most common variety. The

point of entry and point of exit are quite far apart, therefore the air has

enough time to cool and condense the water vapour.

In order to avoid this, elements such as barriers are installed, so as to stop the

flow and diffusion of air and vapour.

237

Insulation. An example of its influence

Hollow ceramic brick wall. On the

right we have included the typical

dimensions of one of these

bricks.

Below we can see the different transmittances of the wall depending on the type

of installation.

Simple brick wall

Thermal conductivity of the brick: 0.49 Km

Wº

KmWU

WKmeR

RU T

T º5.3;º285.0

49.014.0;1

2

2

=====λ

Double brick wall with air chamber

Thermal resistance of the air chamber: 0.18 W

Km º2

KmWU

WKmR

RRRRU T

ladaireladT º33.1;º75.0

49.014.018.0

49.014.0;11

2

2

==++=++

==

Double brick wall with insulation

Thermal resistance of the insulation (expanded polystyrene): 0.046 W

Km º2

KmWU

WKm

RRRRR

U TladillamladT º

6.0;º

657.149.014.0

046.005.0

49.014.0;11

2

2

==++=++

==

238

Thermal bridge.- this is the definition used for any type of discontinuity in the

thermal insulation capacity. That is to say, a greater capacity for heat to be

transmitted in areas where the discontinuity is present.

Doors. Types At a very basic level, we can distinguish between interior doors, which provide

access to the different rooms in a single dwelling, and exterior doors, which

provide access to the dwelling from the outside or from common areas (balcony

doors or front doors).

With regard to the type of manufacturing process, these can be made of wood

or metal, and they can also include different types of glazing.

Whenever exterior doors are glazed (such as balcony doors) it is necessary for

them to comply with the same requirements as windows: thermal bridge framing

and double or triple glazing with air chamber/s.

In so far as the operating system of doors, these can be classified as follows:

• Hinged doors: these include a traditional locking system such as a door-

knob or handle; they are the most commonly used variety.

• Sliding: they slide using horizontal rails.

• Swinging doors: very practical, but due to their characteristics, they are

not very adequate for limiting acclimatized rooms.

Solar radiation.- the radiation and transfer of energy by means of

electromagnetic waves.

This is directly produced outward from the source in all directions.

239

Electromagnetic waves do not need a material means to propagate. Therefore,

these waves can cross space and reach the Earth from the Sun.

Composition: Visible light 43%, near infrared 49%, ultraviolet 7%, and the

remaining 1% in other ranges.

Thermal resistance.- this is the measurement of a body’s ability to stop

calorific or thermal energy flowing through it.

Expression: ( )

⎟⎟⎠

⎞⎜⎜⎝

⎛=⎟⎟

⎠

⎞⎜⎜⎝

⎛

CmWmE

WCmRT

º

º2

λ

Heat transfer.- the transmission of heat from a building takes place as shown in

the following diagram:

Through the enclosure the transmission of heat is produced by conduction,

whilst in the interior environment, as well as between the enclosures and the

exterior surroundings, the exchange is produced by a combination of the two

mechanisms of convection and radiation.

240

Heat transmission by conduction.- conduction is the transportation of heat

through a substance and it takes place whenever there is contact between two

objects with different temperatures. The heat flows from the object which is at a

higher temperature to the one which is colder. The conduction continues until

both objects reach the same temperature (thermal equilibrium).

The resistance (insulation) to the transmission of heat depends on the inherent

characteristics of the materials, such as their thermal conductivity (λ) and

thickness (E).

Heat transmission by convection.- this is a way of transferring heat

characterized by the fact that the heat flows through an environment in which

the movement of particles is relative.

There are two types of convection:

• Natural.- this is due to the thermal gradient. Because of the difference in

density or specific weight resulting from the difference in temperatures,

making the colder fluid descend whilst the warmer ascends.

• Forced.- this is produced when mechanical means are used to provoke

or increase the movement of the fluid.

Heat transmission by radiation.- a means of transferring heat influenced by

the characteristics of the material, even though there does not need to be any

contact between the source and the receptor.

Opaque bodies emit radiation. Being able to emit is related to the way in which

a body absorbs or reflects the radiation it is exposed to.

A material which is a good reflector of radiation is a bad absorber, and vice

versa, a bad reflector is a good absorber.

241

On the other hand, a good absorber of radiation is a good transmitter, and vice

versa, a bad absorber is a bad transmitter.

By combining the two aforementioned expressions, we can conclude that a

good reflector will be a bad transmitter, and similarly, a bad reflector will be a

good transmitter.

In the following table we have presented the capacities of different materials to

reflect solar radiation, in descending order:

Thermal transmittance (U)

Definition: the opposite of thermal resistance. Units: 2 ºKcal

m h C⋅ ⋅, 2 º

Wm C⋅

High U: metals, (very high); stone material (moderately). Low U: wood; air, even though it is not exactly a material, it has a very low

conductivity, as long as it is not moving.

Glass. Types

Aluminium (polished) 95% Whitewash 88% White paint 80% Galvanized steel 75% Slate, gravel, concrete 40% Fibro cement 10% Roof tiles 7%

242

High reflectivity glass.- it has been processed so as to have an exterior

surface which appears to be mirror, with a reflectance of 45%. It reflects

visible radiation as well as the thermal kind.

Low reflectivity glass.- by carrying out specific processes on the surface,

the typical reflection of glass can be reduced to less than 1%. This is

appropriate whenever visual conditions are of the utmost importance.

Low emissivity glass.- the arrangement of silver sheets provides the

characteristics of low emissivity due to its high reflectivity in far infrared

whilst layers of transparent metal oxides act like antireflection layers in

the visible range, achieving a high transparency rate.

High absorption glass.- by incorporating metal oxides the absorption of

light and heat can be increased. The absorbed energy heats the window

pane, and a considerable proportion is dissipated toward in the interior,

therefore they are not adequate in warm climates.

Very low absorption glass.- for important transparency needs, even with

large thicknesses.

Glass. Reaction to solar radiation

Simple transparent glass

allows a considerable

amount of visible radiation to

pass through (around 89%).

The rest, which is about 8%,

is absorbed proportionally

depending on the thickness

of the glass, and in the case

of 6mm glass panes, this

lies around 3%.

243

Glossary of technical acclimatization terminology:

Term Unit Description/Definition

Boiler

The ensemble designed to transmit heat to water by means of the combustion of a solid, liquid or gas fuel; it is made up of a body and a burner.

Standard boiler A boiler with an operating temperature that can be limited depending on its design. It

does not admit return flow water temperatures below 60 ºC.

Low temperature boiler

A boiler that can work continuously with a water supply temperature between 35 and 40 °C and which may produce condensation in specific circumstances from the water vapour which is present in the combustion gases without significantly damaging the boiler.

Condensing boiler

A boiler designed to be able to permanently condense a significant proportion of the water vapour which is present in the combustion gases. The condensation allows the heat from the water vapour produced during combustion to be recovered, thereby obtaining an energy performance slightly above 100%, with reference to the Inferior Calorific Power (I.C.P).

Partial load % Relationship (expressed using a percentage) between the useful output of a boiler which is operating at less than the nominal useful output, and the nominal useful output itself.

I. C. P.: Inferior calorific power

The quantity of heat emitted by the complete combustion of 1 kg of solid or liquid fuel, or of 1 m3 of gaseous fuel, at a constant pressure of 1.01325 bar and a temperature of 25 °C, at which supposedly any water derived from the humidity of the fuel and from the combustion itself as evaporated. The following table shows the corresponding values for some fuels:

Type of fuel Propane Gas Butane Gas Natural Gas C diesel oil

Approximate I.C.P. (Kcal/kg) 11,100 11,000 8,950 9,700

Nominal thermal output

The maximum calorific output produced by the boiler when it burns fuel. This nominal output is determined by the product of the consumption (quantity of fuel per unit of time) by the inferior calorific power at a constant pressure -ICP- of that fuel.

Useful thermal output

The maximum quantity of energy per unit of time that the generating equipment transmits to the heat-carrying fluid in an acclimatization system. It is different to the nominal thermal power because of the efficiency of the generating equipment.

Boiler efficiency %

Relationship (expressed using a percentage) between the heat flow transmitted to the water in a boiler, and the product of the inferior calorific power of the fuel at a constant pressure (I.C.P.) by the consumption expressed in quantity of fuel per unit of time, that is to say, the quotient between useful output and nominal output.

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Glossary of technical illumination terminology:

Photoelectric cell -

A device which harnesses the photoelectric effect converting the luminous impulses into an electric current, whereby the ignition and shut-down of public lighting can be controlled.

Astronomic clock -

A device designed to turn public lighting on and off, coinciding exactly with daybreak and sunset in the place they are located. The function of astronomic control is based on determining the sunrise and sunset hours at a specific location, for any day of the year, by using information regarding longitude and latitude. In order to control the illumination, it includes two independent circuits: the solar circuit to control the ignition and shut-down coinciding with sunrise and sunset, and also the voluntary control circuit, by means of which the ignition and shut-down times are programmed by the user, within the solar ignition timeframe, with different control programmes for summer and winter. Given the characteristics of this type of equipment, it can be installed without taking any exterior light references, which is an advantage for the complete independence from exterior elements. All of the operating information is stored in the equipment’s memory and it can be modified by the user at any time, either manually, using the external buttons, or automatically by means of a communication link connected to a PC type terminal.

Average Daylight Factor -

The average indoor illuminance on a reference plane or planes (usually the working plane) as a percentage of the simultaneous outdoor illuminance from the unobstructed sky.

Ballast -

Equipment used with discharge lamps for stabilising the discharge. The ballast allows the lamp to start and to run in such a way so as to provide the right amount of light while maximizing the life of the lamp. The basic kinds of fluorescent ballasts are:

Electromagnetic (also called magnetic or “core & coil”): these are the oldest, the least efficient and the heaviest.

Electromagnetic with reduced loss: these are electromagnetic ballasts which have reduced loss because of better materials applied.

Hybrid: these are basically electromagnetic ballasts with a slight twist. They have the same components as the core & coil but with a small bit of electronic circuitry to disconnect the cathode heater windings after a rapid start lamp is ignited. This saves about 3 watts per lamp.

Electronic: these are the most energy efficient due to their high frequency operation.

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Brilliance - The effect of light on glossy surfaces or transparent material. Brilliance is caused by the reflection of the light source or refraction of the light; it requires incident light from narrow beam light sources.

Starting device

A device used with fluorescent lamps in order to provide the necessary preheating of the electrodes; in combination with the electromagnetic ballast, it also provokes a momentary voltage in the lamp.

Colour rendering index (Ra, IRC)

-

A term used to qualify a light source (ranging from 0 to 100). Objectively, it can be defined as the colour of a truly white surface illuminated by the source (If the picture is identical with original, the index is 100). It indicates how perceived colours match actual colours. The higher the colour rendering index, the less colour shift or distortion occurs.

Colour Temperature of a source

K

It expresses the colour appearance. The higher the temperature, the cooler the light source appears to be. Colour temperatures of 4000 K or higher appear white and cool; colour temperatures of less than 3000 K have a warm colour appearance e.g. incandescent lamps (see correlated colour temperature).

Visual comfort The characteristic which manifests the absence of disturbances in the visual environment.

Contrast Subjective sensation of the difference in appearance between two parts of the visual field. It is usually quantified as: (L2-L1) / L1. L1: Predominant background luminance, L2: Object Luminance.

Control gear -

Control gear is the equipment required to operate a lamp. It consists mainly of current limiting ballast and starter devices for the operation of discharge lamps, as well as transformers to operate low-voltage halogen lamps. Inductive gear is available either in conventional or low-loss versions; an additional ignitor or starting device can be required.

Compact fluorescent lamps

-

Single-ended fluorescent lamp with a bent discharge tube of small diameter, of around 10-16 mm, to form a very compact unit (similar to a tungsten standard lamp).They have fundamentally the same properties as the conventional fluorescent lamps; these have a high luminous efficacy and average lifetime (between 6,000 and 15,000 hours). The relatively small volume of the discharge tubes can produce a focused light using the luminaire’s reflector. Compact fluorescent lamps with integrated starters can usually not be dimmed. However, there are types with external starters available, which can be operated on electronic control gear and allow dimming.

Crest factor -

It is the ratio of peak current to average current. Applications with a high crest factor can cause materials to be eroded from lamp electrodes, prematurely shortening lamp life. Electronic ballast crest factor are 1.7 for rapid start lamps and 1.85 for instant start lamps.

Correlated Colour Temperature

K

The temperature of a full radiator that emits radiation having a chromaticity nearest to that of the light source being considered. As an example, the colour of a full radiator at 3,500 K is the nearest match to that of a white fluorescent lamp, which is therefore said to have a correlated colour temperature of 3,500 K.

246

Cut-Off angle °

A term applied to a luminaire. The angle measured from the downwards vertical upwards to the first line of sight at which the lamp(s) or surface of high brightness is no longer visible. This angle is usually measured from the downward vertical or, for a flood light, from the beam axis.

Glare The visual discomfort produced when parts of the visual field are very bright in relation to the surroundings to which the eye is adapted.

Dimmer -

Devices for continuous regulation of power input by lighting system according to daylight intensity. Applying of dimming in outdoor lighting is one of the measures which can bring electricity savings. It is appropriate to apply in night hours, but also continuous dimming of the lighting system on sunrise and sunset instead of step on/off. Dimming can be made manually or automatically.

Discharge lamp -

Lamp in which the light is produced by an electric discharge through a gas, a metal vapour or a mixture of gases and vapours. All discharge lamps have to operate with a ballast in their electric circuit. This is to control the lamp current.

Efficacy lm/W This term is typically used to quantify how efficiently a lamp turns electricity into light. The higher the efficacy, the more efficient the lamp.

Efficiency of a luminaire -

When a lamp is placed in a luminaire (a light fixture) not all of the lamp’s light makes it out of the luminaire. The percentage of light from the lamp(s), which is emitted by the luminaire, is its efficiency.

Electric lines - Overhead lines or cables.

Fluorescent lamps -

A high intensity discharge lamp in which the light is produced by an electric discharge through a vapour of mercury operating at low pressure. They consist of a sealed glass tube, coated on the inside with phosphors and filled with an inert gas and a small quantity of mercury. An electrical discharge within the tube excites the mercury atoms which emit radiation predominantly in the ultra violet. This UV radiation is converted to visible light by the phosphors. Fluorescent lamps are available with different diameters, inert gas fillings and phosphor coatings. The colour properties of fluorescent lamps are determined by the phosphors used to coat the inside of the tube. A mixture of phosphors is used to produce a white colour appearance, but this can vary in colour temperature depending on the relative proportions of the phosphors in the mixture. The phosphor mixture also determines the colour rendering properties of the lamp. All fluorescent lamps require ballasts to provide appropriate electrical conditions for starting and for control of the discharge. Fluorescent lamps feature a high luminous efficacy and high lifetime. They ignite immediately and attain their full luminous power after a brief moment. An immediate re-ignition is possible if the current is interrupted. Fluorescent lamps can be dimmed depending on the control gear. For applications with low temperatures specific fluorescent lamps must be applied. Luminous intensity decreases noticeably at temperatures below minus 10°C.

247

Maintenance factor The quotient between the illumination supplied by an installation at

any given moment and when it was installed.

Geometry of lighting system - Geometry arrangement is given by distance between poles, overhang,

tilt angle, mounting height.

High intensity discharge (HID) - This term defines a class of lamp made up of the following lamp types:

metal halide, high pressure sodium and mercury vapour.

High Pressure Mercury Vapour Lamps (HME, also called MBF)

-

A high intensity discharge lamp in which the light is produced by an electric discharge through a vapour of mercury operating at higher pressure than in fluorescent lamps (mercury vapour pressure is typically around ten atmospheres). Like in fluorescent lamps, the arc tube is filled with argon and a small quantity of mercury. A fluorescent coating on the inside of the outer envelope converts the long wave UV radiation into visible light. When operating the lamp, at first a low pressure arc exists and very little light is produced; but gradually, as the lamp heats up, the mercury vapour pressure rises and a high-pressure arc is formed and more light is emitted. The time taken for the lamp to reach full light output is approximately 5 minutes.

High pressure sodium lamps (HST, HSE or SON)

-

A high intensity discharge lamp in which the light is produced by an electric discharge through a vapour of sodium operating at high pressure. These lamps have excellent luminous efficacy and a high nominal service life. Their colour rendition is moderate to good. They require an ignition time of several minutes and a cooling-down phase before being re-ignited. In some forms an immediate re-ignition is possible using special starters or the electronic control gear.

Indoor lighting - This includes the lighting of buildings, industrial warehouses, sport halls, family dwellings, etc.

Illuminance or illumination level lux

The luminous flux incident on unit area of a surface (luminous flux in lumens / area illuminated in m2). The unit is the lux (one lumen per square metre).

General illumination Illumination designed to illuminate everything with the same

approximate illuminance.

Local illumination Illumination designed to illuminate a specific, additional and controlled

task, separate from the general illumination.

Illumination - The process of lighting an object or surface.

Incandescent lamp - A lamp where a filament is heated by an electric current to produce

light.Incandescent light bulbs have a very low efficacy.

Induction lamp Compact electrodeless fluorescent lamp where the discharge is induced by a high frequency energy flux.

Lighting source or lamp -

A lamp is a source of illumination. The electric light sources can be divided into three main groups, divided according to how they convert electrical energy into light. One group is that of the thermal radiators (incandescent lamps and tungsten halogen lamps), the second group is made up of the discharge lamps (e. g. all forms of fluorescent lamps, sodium vapour lamps and metal halide lamps), and the third group consists of the semiconductors with the LEDs.

248

Lighting system -

Lighting systems are properly arranged light points given by the geometry of the lighting systems. Systems of street lighting are also a system of electrical devices : luminaries, poles (with electro-installation), distribution boxes and electric lines.

Linear fluorescent lamp (or tube)

Fluorescent lamp of straight tubular form and bipin electrical connections at either end.

Low Pressure Sodium Lamp (LST or SOX)

-

A high intensity discharge lamp in which the light is produced by an electric discharge through a vapour of sodium operating at low pressure. These lamps are the most efficient light sources available. This means that they deliver more lumens of light for each watt of power than any other type of lamp. The principal reason for the high efficacy is because the light is emitted monochromatically at a wavelength very close to the maximum sensitivity of the human eye in normal viewing conditions. Because of the monochromatic light (only one wavelength), no colour can be distinguished in the light.

Luminaire - Device which controls the distribution of flux from a lamp or lamps, and which includes all the components necessary for fixing and protecting the lamps and for connecting them to the local supply grid.

Luminance cd/m2

This term expresses the intensity of light emitted in a given direction by unit area of a luminous or reflecting surface. It is the physical equivalent of what is subjectively called brightness. The eye is very good at distinguishing between different luminance values.

Luminous Efficacy lm/W

The ratio of the luminous flux emitted by a lamp to the electrical power consumed by it. Luminous efficacy indicates the efficiency with which the electrical power consumed is converted into light.

Luminous Flux lm

The light emitted by a source or received by a surface. Describes the total light power emitted by a light source. It is calculated using the spectral radiant power and the spectral sensitivity of the eye. Unit: lumen.

Luminous Intensity cd The power of a source to emit light in a given direction. Unit: candela.

Metal vapour lamps -

A high intensity discharge lamp in which the light is produced by an electric discharge through a vapour of a metal halide. Metal halide lamps feature excellent luminous efficacy and excellent colour rendition. They represent a compact light source. The light can be optically well directed. The colour rendition is not constant. Metal halide lamps are not dimmed. They require an ignition time of several minutes and a longer cooling-down phase before re-igniting. In some forms an immediate re-ignition is possible using special starters or the electronic control gear.

Mounting height m The vertical distance between the luminaire and the ground or floor, or between the luminaire and some other specific plane.

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Outdoor lighting - Covers the following lighting areas: illumination of public communications and places, urban areas, local routes, roads, streets, highways, pedestrian walkways, cycle paths, tunnels, subways and underpasses, bridges, crossings, passages, parks, pedestrian and residential zones, bus stations, car parks etc.

Work surface A horizontal surface upon which the average illuminance is calculated. For offices and similar buildings, it is usually established at 0.85 metres from the floor.

Photo sensors -

A photo sensor is an electrical device that measures the current amount of available daylight, and then adjusts the level of electric lighting accordingly. The key to the success of this control technology is the photocell placement and calibration. Photo sensor calibration must be easy and accurate.

Power factor - Power Factor is a measure of how efficiently ballast convert the voltage and current supplied from the power source into usable power (watts).

Radiant power W In electric lamps, the converted product of electrical power. Physical unit: Watt. In the 380 nm to 780 nm wavelength, radiant power (W) can be quantified as luminous flux (lm).

Reflectance - Is defined as the ratio of luminous flux reflected from a surface to the total incident luminous flux. It is expressed either as a decimal or as a percentage.

Reflector - A device for controlling the flux from a lamp by reflection on suitable shaped surfaces. These may be either specular (e.g. mirrored glass or polished aluminium) or diffuse (e.g. vitreous enamel).

Starter - Control gear causing the ignition of discharge lamps by creating voltage peaks.

Transmittance (Transmission factor)

- The ratio of the flux transmitted by a material to the incident flux upon it.

Total harmonic distortion (THD) -

If an electrical device (such as an electronic ballast) connects a non-linear load, the current wave shape will be distorted (no longer a sine wave) and harmonic currents will flow. This can cause electrical problems and should be limited (EN 61000-3-2).

Overall luminance uniformity

-

It is the ratio of minimum illuminance to average illuminance. It refers to the visibility of the surface of the road which acts as a background for road markings, obstacles and other users of motor vehicle throughfares.

Longitudinal luminance uniformity

-

Uniformity of horizontal lighting can be counted as minimum illuminance to maximum illuminance. It reflects the repetition of transversal strips on the road surface, alternately bright and dark. It is related to the visual conditions when driving along a road and to the visual comfort of the driver.

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GLOSSARY

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(agua) (water) (hielo) (ice) Acumulador liquido Liquid accumulator Acera Pavement Acumulador Accumulator Adaptador de potencia Power adaptor Aire arrefriado Cooled air Aire enviado o exterior (48 ºC) Air sent to the exterior (48 ºC) Aire exterior (35 ºC) Exterior air (35 ºC) Aire extraido do local mais aire exterior (renovacion)

Air removed from the premises and exterior air (renovation)

Aire frio deshumidificado Dehumidified cold air Aire habitacion Interior environment air Aire humido do recinto Humid air from the environment Aire impulsado o local (15 ºC) Air pumped into the premises (15 ºC) Altura de los cuerpos de hielo congelados Height of the frozen ice masses Altura de los cuerpos de hielo no congelados

Height of the non-frozen ice masses

Ampola Bulb Anel de ferrita Ferrite ring Auga a piscina Water into swimming pool Auga da piscina Water from swimming pool Baixa temperatura Low temperature Bo Good Bobina Coil Bomba circulacion Circulation pump Caldeira Boiler Calor Heat Calzada Roadway Cámara de aire Air chamber Camara: argon ou cripton no espazo entre os vidros

Chamber: argon or krypton in the space between the panes

Cambiador placas Parallel plate heat exchanger Campo electromagnetico Electromagnetic field Casquillo Cap Central de regulacion Main control panel Compresor Compressor Condensacion Condensation Condensado Condensation Condensador Condenser Conduccion Conduction Consumo Consumption Control Control

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Conveccion Convection Convencionais Conventional Corrente electrica Electric current Cuerpos Masses Decembro 21 21st December Dispositivo de expansion Expansion device Electrodo Electrode Electrodo de arranque Starting electrode Electrodo principal Main electrode Electrodos principais Main electrodes Emisor Transmitter Enerxia disipada o exterior Energy dissipated out into the exterior Evaporador Evaporator Evaporador (deshumidificador) Evaporator (Dehumidifier) Exterior Exterior Filamento Filament Fio conductores Contact wires Fluxo dos electrons Electron flux Gas de mercurio Mercury gas Gas de recheo Low pressure inert gas Gas frio Cold gas Gas quente Hot gas Hora solar Solar time Intercambiador de calor Heat transfer unit Intercambiador de calor de agua Water heat exchanger Interior Interior Inverno: calor reflexado cara o interior, axudando a manter quente a vivienda

Winter: heat reflected towards the interior, helping to keep the dwelling warm

Lampada fluorescente de alta potencia sen electrodos

High power electrodeless fluorescent lamp

Liquido refrixerante frio Cold refrigerating fluid Mal Bad Manometro Manometer Mar. e Set. 21 21st Mar. and Sept. Mediodia Midday Motor Motor Porcentaxe absorbida Absorbed percentage Porcentaxe reflectida Reflected percentage Porcentaxe transmitida Transmitted percentage Queimador Burner Radiacion Radiation Radiacion incidente Incidental radiation Recubremento fluorescente Fluorescent lining Reenviada o exterior Transmitted back out to the exterior Reenviada o interior Transmitted back into the interior

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Reflector Reflector Refrixerante condensado Condensed refrigerant Refrixerante en estado gaseoso alta temperatura e presion

Refrigerant in gaseous form at high temperature and pressure

Refrixerante liquido a alta temperatura e presion

Refrigerating liquid at high temperature and pressure

Refrixerante practicamente liquido a baixa temperatura e presion

Virtually liquid refrigerant at low temperature and pressure

Resistencia de arranque Starting resistance Retorno de aire quente deshumidificado o recinto de piscina

Dehumidified hot air return flow into the swimming pool environment

Semáforo de peóns con indicación de tempo restante para cruzar

Pedestrian traffic light including a ‘time remaining’ countdown

Semáforo de vehículos Vehicle traffic light Soporte Support wires Soporte de montaxe Mounting support Tanque Tank Termostato Thermostat Traxectoria solar Sun’s trajectory Tubo de descarga Discharge tube Tubo fluorescente Fluorescent tube Unidade exterior Exterior unit Unidade interior Interior unit Valvula antiretorno Non-return valve Valvula de 4 vias 4-way valve Valvula de expansion Expansion valve Valvula tres vias motorizada Motorized three-way valve Vastago Stem Ventilador Ventilator Ventilador condensador Condensation ventilator Ventilador evaporador Evaporation ventilator Veran: calor reflexado cara o exterior, axudando a manter a casa fresca

Summer: heat reflected towards the exterior, helping to keep the house cool

Volumen para la expansion de los cuerpos Volume for ice mass expansion Xerador de alta frecuencia High frequency generator Xuño 21 21st June

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BIBLIOGRAPHY

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Publications:

• Roca technical catalogue.

• Sedical technical catalogue.

• Viessmann technical catalogue.

• Spirax-Sarco vapour course, 2004.

• Study: Energy optimization in the hotel industry in Galicia. Inega, June 2004.

• Sectorial study into cogeneration in Galicia. Inega, October 2004.

• Home energy guide. Inega.

• Energy guide. Efficient and responsible consumption. IDAE, 2004.

• Luminotecnia. Indalux, 2002.

• Manual: Fuel efficient driving for State chauffeurs. IDAE, 2002.

• Manual: Building insulation. ISOVER.

• Climatization and energy price list. Frigicoll, May 2006.

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Web sites:

http://www.americansignalcorp.com

http://www.apein-lumtec.com

http://www.carrier.es

http://www.elt.es

http://www.eu-enlight.org

http://www.eu-greenlight.org

http://greenbuildings.santa-monica.org

http://www.idae.es

http://www.iea.org

http://www.intertraffic.com

http://www.lighting.philips.com

http://www.metrolight.es

http://www.novatron.com.br

http://www.orbis.es

http://www.osram.es

http://www.syndicat-eclairage.com

http://www.thermosolar.it

http://www.wbdg.org

GUIDE TO PROCURING EQUIPMENT AND DESIGNING BUILDINGS … · 2014-08-11 · ¾ The traditional lightin g system based on incandescent lamps, made up of: Filament lamps (incandescent

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