S-AA-ELMS-HVAC+VENT (Rev.0-2009)

STANDARD TECHNICAL SPECIFICATIONS FOR ELECTRIC WORKS

ELECTRO-MECHANAL SERVICES

( SPECIFICATION )

AIR-CONDITIONING AND VENTILATION SYSTEMS

document.doc Page 1 of 34

SWITCHGEAR

HV/EHV Switchgear Protection Schemes

ADDC/AADC STANDARD : DOCUMENT.DOC


ELECTRO-MECHANICAL SERVICESAir-Conditioning and Ventilation Systems

CONTENTS

1 GENERAL....................................................................................................41.1 Drawings.....................................................................................................................51.2 Equipment Identification and Color Codes................................................................5

2 TECHNICAL DESCRIPTION...................................................................52.1 HVAC Works.............................................................................................................52.2 Design Criteria for the HVAC-Systems.....................................................................72.2.1 General System Design Requirements....................................................................72.2.2 Design Indoor Air-Conditions.................................................................................82.2.3 Design Outdoor Air-Conditions..............................................................................92.2.4 Heat Transmission Data..........................................................................................92.2.5 Fresh Air Rate.......................................................................................................102.2.6 Air Change Rate....................................................................................................102.2.7 Space Pressurization..............................................................................................102.2.8 Air Filtration..........................................................................................................102.2.9 Air Flow Velocities...............................................................................................112.2.10 Load Calculation Figures......................................................................................112.2.11 Design, Drawings, Approval of Materials and Equipment...................................122.3 System Design Features............................................................................................132.3.1 General Design Concept........................................................................................132.3.2 HVAC-System for the Control, Electronic and Communication Rooms and

related Areas..........................................................................................................142.3.3 HVAC-System for the Switch-Gear Halls and Related Areas..............................142.3.4 Ventilation System for the Indoor Power Transformer Boxes..............................152.3.5 Ventilation System for Cable Floors, Basements and Cable Tunnels...................162.3.6 Exhaust System for the CO2-Gas Flooded Rooms................................................162.3.7 HVAC-System for the Battery Room...................................................................162.3.8 HVAC-System for the Social and Sanitary Rooms..............................................172.3.9 HVAC-System for Fire Pump Room....................................................................172.4 Equipment and Materials..........................................................................................172.4.1 Air Cooled Condensing Units (ACCU)...............................................................172.4.2 Air Handling Units (AHU)....................................................................................182.4.3 Refrigeration Piping..............................................................................................192.4.4 Condense Water Drain Pipes.................................................................................192.4.5 Refrigerant Pipe Insulation....................................................................................192.4.6 Air Extract/Exhaust Fans (E.F.)............................................................................192.4.7 Electric Air Re-Heaters (EH)................................................................................202.4.8 Air Outlets and Air Inlets (Registers, Grilles, Diffusers and Valves)...................202.4.9 Louvers..................................................................................................................212.4.10 Air Dampers..........................................................................................................212.4.11 Access Doors (AD)...............................................................................................222.4.12 Air Filters (AF)......................................................................................................22



2.4.13 Sound Attenuators (SA)........................................................................................232.4.14 Anti Vibration Mountings.....................................................................................232.5 A/C Control System and Control Panels..................................................................242.5.1 General..................................................................................................................242.5.2 Motor Control Cubicles.........................................................................................242.5.3 Automatic Control System....................................................................................25

3 SERVICE AND MAINTENANCE...........................................................26

4 OPERATION AND MAINTENANCE MANUALS...............................26

5 TESTING, ADJUSTING AND BALANCING........................................275.1 General......................................................................................................................275.2 Approval by Public Authorities................................................................................275.3 Job Conditions..........................................................................................................285.4 System Test Start-Up................................................................................................285.5 Functional and Performance Tests...........................................................................285.5.1 Test of the Air Systems.........................................................................................285.5.2 Sound Test.............................................................................................................295.5.3 Reliability Tests.....................................................................................................29



AIR-CONDITIONING AND VENTILATION SYSTEMS

1 GENERAL

The scope of work comprises the design calculation, engineering, preparation of shop drawings, obtaining approvals, procurement, manufacture, supply, factory testing, marking, packing, shipping, transportation to site installation, testing and commissioning of the plant to obtain a complete and fully functional air-conditioning and ventilation system including power / control panels, automatic control and related cabling and wiring according to the requirements of the Contract Documents.

This specification shall be applicable for MV substations and any combination of them. Further detailed and specific data are contained in the drawings, Technical Data Sheets and other documents that form part of these Specifications.

It is not the intent to specify completely herein all the details of design and manufacturing of the functional air-conditioning and ventilation systems. It may be noted that norms specified are the bare minimum that is required. The HVAC System shall conform in all respects to high standards of engineering design and workmanship and should be capable of performing continuous commercial operation within the parameters guaranteed by the Bidder/Contractor in a manner acceptable to ADDC/AADC, who will interpret the meanings of drawings and specifications and shall have power to reject any material, which in his judgement is not in accordance with the specifications and the guaranteed parameters.

All equipment, parts and components as well as any kind of work, services, safety measures, test and samples not mentioned nor particularly specified but essential and required for the proper and normal operation, service or maintenance of the systems, shall be included in the design/construction package.

The conceptual layout, system description and operation, design, calculations, shop drawings, materials and equipment of all HVAC-systems shall be submitted to ADDC/AADC for his review and approval, before the Bidder/Contractor may start with the fabrication, construction, erection and installation work.

Different interpretation of the contract meaning, if any, will be clarified and decided by ADDC/AADC.

Air-Conditioning and ventilation systems shall be selected, calculated, designed, manufactured, executed and tested in conformity with the latest issues of the relevant and internationally recognized codes and standards such as ASHRAE, ASME, SMACNA, ARI, NFPA, DIN, VDI, VDE, BS, JS as well as all local laws and regulations.



Calculation of heat loads and losses, cooling loads, ventilation and air flow requirements shall be made in accordance with the ASHRAE Standard for Cooling Load Calculation and with the Duct System Design Method.

Commercially available cooling load and duct system design programs from Carrier or others may be used for load calculation and the results of the calculation process shall be submitted along with a hard and a soft copy of the calculations.

The Bidder/Contractor may submit to ADDC/AADC any applicable national standard for approval if it is at least equivalent to the codes and standards mentioned above.

Tests on equipment and duct work for proper functioning, air-tightness and guaranteed data shall be undertaken according to the related Standards and shall be performed according to approved test procedures and test protocols.

The Bidder/Contractor is obliged to co-ordinate in due time the design, installation and integration of the air-conditioning and ventilation system at the building with the related design and construction requirements of the architectural, civil, electrical and mechanical works.

For applicable technical standards, tests and general requirements, reference shall be made to:

S-AA-ELMS-GEN - General Requirements(Applicable Technical Standards, Tests, etc.)

1.1 Drawings

For Air-conditioning and Ventilation Systems Details, reference shall be made to the below listed drawings, which are provided in the Drawings Section:

Drawing No. Title

DWG AA ELMS 01 01 Schematic Air Flow Diagram for a Typical Substation

DWG AA ELMS 01 02 H.V.A.C. Control Panel Fascia

1.2 Equipment Identification and Color Codes

Concerning Air-Conditioning and Ventilation Systems Identification, reference shall be made to Standard Technical Specification, Part:

S-AA-GEN-ID - Components Marking



2 TECHNICAL DESCRIPTION

2.1 HVAC Works

All equipment shall be installed according to the requirements of this Specification and by following the manufacturer's instructions and recommended best practice, and as per approved drawings and in accordance with the directions of ADDC/AADC on site. All necessary shims, anchor bolts, hangers, brackets, junction pieces, lubricating oil and other items required for proper installation shall be furnished.

Duct work made of hot dipped galvanized (Z27) steel sheets shall be straight and smooth on the inside with neatly finished joints, flanged connections and shall be air-tight. Sheet metal thickness shall be 0.8 mm for ducts up to 1.0 m width and 1.00 mm for wider ducts.

Changes in dimensions and shape of ducts shall be made in a gradual manner. All ducts or motorized fire dampers passing through partitions or formed openings in concrete walls or floor slabs shall be thoroughly installed in straight alignment.

Where sheet metal ducts are embedded in concrete, the Bidder/Contractor shall take proper precautions to prevent collapsing the sides of the ducts when concrete is being placed. The exposed surfaces of embedded duct work shall be protected against corrosion.

Horizontal duct runs shall be supported with galvanized steel threaded rod and steel angles, hot dip galvanized after fabrication.

Vertical duct risers and other duct runs where the method of support specified above is not applicable shall be supported by substantial angle brackets designed to meet site requirements. The method of support shall be subject to ADDC/AADC's approval, however all supports, brackets etc. shall be hot dip galvanized after fabrication.

All the sheet metal supply air and return air ducts shall be insulated with 38 mm thick rigid fiber glass. The insulation shall be adhered to duct surfaces with an approved adhesive and stick clips. All edges of insulation shall be butted and all joints shall be sealed with a vapor barrier mastic and vapor barrier tape.

All the insulated ductwork shall be wrapped with 6 oz. (minimum) Canvas Cloth with one coat of weather protection and two coats of vapour barrier complying with the requirements of NFPA 90A, NFPA 90B and UL. All the visible and A/C Plant Room installed sheet metal insulated ducts shall have external sheet metal cladding of 0.8 mm thick aluminum sheeting.

Rubber mounts shall be provided between ducts, pipes and the related hangers and brackets.

Wooden pieces treated with wood preservative coating and equivalent to the insulation thickness shall be provided between the insulated duct and pipe and the mounting clamps. The wooden pieces shall be embedded within the insulation and shall be covered by the vapor barrier insulation or cover.



All air ducts shall be equipped with a sufficient lot of access doors and inspection openings of an adequate size for easy inspection, service and cleaning of the duct from inside, for the service, inspection and maintenance of the dampers, electric heaters and of the other entire duct mounted devices and units.

Test holes with plugs shall be provided on supply air ducts, return air ducts and ventilation ducts for static and dynamic air pressure and air flow measurements.

To maintain the specified noise criteria sound attenuators shall be provided in the air supply

return and exhaust ducts. All equipment, components of the plants as well as components for monitoring, controlling, indicating, announcing, acting, switching, alarming, measuring, servicing and maintenance shall be clearly labeled.

The labels shall, depending on the purpose for which they are to be used, be made of either non-transparent or translucent heat resisting synthetic resin, stainless steel or aluminum subject to ADDC/AADC’s approval of samples.

The identification labels for the fire dampers shall be made of trafolite plates with red border, white background and red engraving.

Flow-direction arrow plates shall be provided in the vicinity of branch-off connections, at the inlet branch connections and down stream of all valves and dampers. Pipes, ducts and valves shall be identified by self adhesive tapes in the identification color of the medium transported.

Generally, each mechanical and electrical device shall be provided with an earthing screw of sufficient diameter suitable for connection to the protective earthing system. The Bidder/Contractor is responsible that all metallic housings, ducts, pipes and other parts of the complete installation, such as equipment, fans, pumps, compressors, tanks, fire dampers, filters, etc., are effectively connected by earth conductors.

The Bidder/Contractor shall supply, install and connect all necessary drainage and waterproofing of his ventilation and AC plants. The drainage and waterproofing shall include all drain pans, condensed water drains, siphons, and funnels and drain pipes connected to the next floor drain.

All relevant safety regulations shall be observed carefully. All heavy equipment such as ACCU, AHUs, pumps, fans, etc., shall be placed on concrete foundations with sub-layers of anti-vibration material to avoid the conduction of vibrations from the noisy equipment through the building structure into surrounding areas and spaces. Where necessary, the equipment shall be set up on additional spring type anti-vibration pads or isolating rubber.

The air handling units shall be installed in a separate room of sufficient size for easy and proper maintenance with the following minimum clearances to the equipment (but not less than the manufacturer’s recommended clearances):



Front side : 1.5 m

Rear side : 1.0 m

Other Sides : 1.0 m

Between two AHUs : Width of the AHU + 0.2 m.

and with sufficient clear height (>5m) to accommodate the duct work under the roof or floor slab and beams.

The A/C-plant room doors shall have a sufficient opening size to allow for the easy and complete removal of the AHUs.

2.2 Design Criteria for the HVAC-Systems

2.2.1 General System Design Requirements

The HVAC systems shall be designed for a trouble-free, continuous, safe, effective and economic operation of the entire HVAC plant and of the served electric, electronic, mechanical and civil installations and substation operating personnel if any.

Stand-by capacities shall be provided as mentioned below and shall include an automatic switchover function in case of a unit failure as well as suitable control and indication facilities at approved locations.

The systems shall be designed to serve as a centralized air-conditioning system all areas and spaces of the entire S/S. with air conditioned air.

2.2.2 Design Indoor Air-Conditions

Area / Space Summer DB Temperature

oC

Winter DB Temperature

oC

Air Humidity[% r. h.]

Room Noise Level from HVAC

dB(A)

Unit’s Capacity Split

(%)

Offices, Social Rooms Control, Computer, Telecom Rooms, SCMS Electronic and Relay Rooms and similar Rooms

23 ± 2 K 21 ± 2 K 50 ± 10 40 2 x 100

Switchgear Rooms for MV S/S. Battery & Charger/LVDC rooms,

27 ± 2 K 21 ± 2 K n.a. 50 3 x 50



LVAC Distribution, and A/C Plant Room and similar Rooms

CO2-Bottles Rooms, Stores, Janitor Rooms, Staircases, Corridors, Indoor Aux. Transformer, Capacitors, Reactor, Compensator and Inverter Rooms, Trenches/Shafts and similar Rooms

30 ± 2 K 25 ± 2 K n. a. 60 3 x 50

Power Transformer Room < 65 < 45 n. a. 45 dB(A) outdoor, measured in 10 m distance from unit

3 x 50

(Ventilation only)

Note: If rooms of different standby percent requirements are grouped under one system due to practical reasons the higher percentage standby (i.e. 100%) shall be considered without any financial impact.

It should be noted that if RH% controlled rooms and RH% uncontrolled rooms are grouped under one system due to practical reasons both these types of rooms have to be considered in the calculation of heater capacity required to control RH% because it is the common return air duct which is the point of sensing.

2.2.3 Design Outdoor Air-Conditions

The design shall be based on the following outdoor air-conditions:

- Max. Wind Speed : 160 km/h

- Occurrence of sand storms : frequently.

Air Temperature and Humidity:

Summer Winter

Max. dry bulb temp 50 °C Min. dry bulb temp 5 °C

Max. wet bulb temp. 31 °C Max. moisture content 100%

Average daily range 14 K



The outdoor air in Abu Dhabi is often very humid and laden with fine sand dust from the desert and salt particles from the seaside.

Thereby the outdoor air is extremely corrosive to all metal parts of the entire structure and installations.

Therefore only the highest available material standard shall be applied with special coating and painting of all exposed surfaces to prevent the equipment from all corrosion effects.

In case of the consideration of an additional auxiliary building for a guard house or a fire pump room or an insulator washing pump room or potable water pump room, separate decorative wall mounted type mini split units with concealed thermostat wiring and refrigerant piping shall be provided to maintain the indoor design temperature of 232 K for guard house and 302 K for other/plant rooms. The capacities of these equipment shall be de-rated for the specified local outdoor air-conditions. In case of non availability of the certified de-rated capacity from the manufacturer of the equipment, the nominal capacity shall be reduced in the design calculation by 30%. A proper condense water connections with drain-traps to the main drain pipes shall be provided.

Any area/room not covered by the a. m. a/c-units shall be air-conditioned according to similar rooms as directed by ADDC/AADC.

2.2.4 Heat Transmission Data

Unless otherwise indicated, the heat transmission coefficient for the cooling load calculation shall be re-checked by the Bidder/Contractor and submitted for approval to ADDC/AADC.

Construction material shall be selected in such a way that the U-values will not exceed the following:

Roof u = 0.45 (W/m2/K)

Outside walls u = 0.45 (W/m2/K)

Windows u = 3.2 (W/m2/K) (for double glass)

Windows u = 1.5 (W/m2/K) (for double glass blocks)

Windows u = 5.6 (W/m2/K) (for single glass)

Steel Doors u = 2.5 (W/m2/K) (insulated)

Aluminum Glass Doors u = 5.6 (W/m2/K).

Data such as U-valves, thermal resistances or thermal conductivities shall be taken only from the following sources

- ASH RAE fundamentals volume



- Carrier design handbook

- Values provided by manufacturers of particular construction materials.

The Bidder/Contractor shall submit the calculations with the actual values and guarantee the proper performance of the HVAC plant.

2.2.5 Fresh Air Rate

The minimum fresh air rate per person shall be 60 m3/h but not less than 5% of the total air flow volume circulated by the AC-system.

In any case the amount of fresh air introduced into an AHU system shall not be less than the following:

- Total amount of air extracted out of the air conditioned area. Plus 5% of the supply air flow rate.

2.2.6 Air Change Rate

Toilets and kitchen 10AC/hr.

Air flow rates into air-conditioned areas shall be determined by the cooling load calculations.

2.2.7 Space Pressurization

Unless otherwise indicated or required, the return air flow rate of the air-conditioned areas shall be 95% of the supply air quantity. This is to create a slight positive pressure in the building to prevent the Infiltration of humid, dust-laden air into the building. However, the battery and CO2

cylinder rooms, kitchen and sanitary rooms shall have slight negative pressure.

2.2.8 Air Filtration

For the classification of the air filtration the ASHRAE standard 52-76 shall be applied. The filter efficiency shall be measured and defined by the dust filter coloration method according to this standard (with synthetic dust). The following filter efficiencies are to be provided for the indicated areas:

Area/Space Air Filter Efficiency

Control Rooms, Electronic Rooms, 85%

Telecom, Computer and Office Rooms 85%

Switch-Gear Rooms, Electric Workshops 75%

Sanitary Rooms, Stores, Other Rooms 75%.



2.2.9 Air Flow Velocities

The maximum air flow velocities shall be as follows:

Room, Equipment Air Flow Velocity (m/s)

In air-conditioned rooms 0.15 - 0.25 at 1.5 m a. fl. l.

Through bag type air filter insets 1.5 - 2.0

Through air cooling coils 1.5 - 2.5

Through air grilles, registers or diffusers 2.0 2.5

Through facade air louvers 1.0 – 1.5

Through perforated floor tiles 1.5 - 1.5

Through main air ducts 5.0 - 7.0

Through branch air ducts 3.0 - 5.0.

The duct work shall be designed on basis of the equal friction method for a maximum friction of 4 Pa/m of duct length (or 0.5 inch per 100 ft).

For the final design of the above-mentioned air flow velocities, the induction effects of the jet air distribution and the maximum allowable sound pressure level shall be considered, too.

2.2.10 Load Calculation Figures

Only the real heat dissipation of the equipment, switch-gears and control panels confirmed by the supplier/manufacturer shall be considered in the design of the HVAC-systems and a copy of these values shall be submitted to ADDC/AADC for approval before the cooling load and the air flow design calculations will be performed.

The heat load from further equipment, switchgear, control panels and cables planned as an extension of the S/S in the future shall also be considered in design.

A safety margin of 10% shall be considered in all design calculations.

Glass shading factor shall be neglected and calculated with 1.0.

Ballast factor of 1.25 shall be considered for fluorescent lamps.

Lighting loads shall be considered with 20 W/m2 for control and relay rooms, communication rooms, offices, social rooms and 15 W/m2 for switchgear and other rooms and areas.

Load calculations to be done by ASHRAE or Carrier load estimating program E20-II.

Design time and date shall be at first computer estimated for the peak solar time for each space to get the peak load.



2.2.11 Design, Drawings, Approval of Materials and Equipment

a) Drawings

The following drawings shall be prepared for the design, construction and commissioning:

Clear architectural/structural drawings without dimensions showing the arrangement of the electric equipment layout (with thin dotted lines)

HVAC layout drawings, 1:100 scale, for the conceptual layout and coordination

HVAC working drawings, 1:50 scale

HVAC construction and assembly details,1:20, 1:10, 1:5, 1:1 scale, as required

Civil work drawings with openings, reservations, block outs and foundation slabs

Separate HVAC drawings for each floor, with necessary sections and elevations.

b) Design

The following steps shall be considered for the design of the HVAC-system:

b1) Preparation and submission of a system description and its functional operation for approval, including the control and alarm systems

b2) Preparation and submission of layout, arrangement, work and as-built drawings

b3) Design calculations.

The following calculations shall be submitted by the Bidder/Contractor:

Tabulation of interior heat loads

Calculation of heating load

Calculation of the cooling load

Calculation of air flow rates

Calculation of make-up air flow rates for the building pressurization

Calculation of static duct pressure drops

Sizing of ducts, grilles, registers, diffusers, valves, dampers, louvers, filters, cooling coils, air heaters, fans, compressors, condensers, refrigerant and drain pipes

Calculation for circuit breaker sizing, cable sizing.

b4) Work and construction drawings

After the approval of system description, the conceptual layout drawings and the design calculations, the work and construction drawings with legend, schedule of materials and equipment, typical details and sections shall be submitted for approval.



c) Approval of materials and equipment

The following documents shall be submitted for the approval of materials and equipment:

At least one complete original catalogue/manufacturer's for each material and equipment (equipment and material data on Bidder/Contractors’ letter head will not be accepted)

Setting values/working range of timer, pressure, temperature cut-out etc., shall be available in the submittals

Data verifying the cooling capacity at 500C along with performance curves, the air flow rates, operating temperatures, voltage, ampere, protection class, insulation class, rated power supply, rpm, details of compressor, motor, blower, fan, coil, casing materials, surface protection

Test certificates, wiring diagrams, graphs for applicable material

Statistics of the climatic conditions shall be available in the manufacturer's literature

Materials and equipment not depending on design calculations, shall be submitted for approval at an early stage as requested by ADDC/AADC

A summary sheet on the cover of each submittal shall state the Content, Revision Number, Date and CSD number of each submittal

Model N°, capacity, details, specification of material and equipment to be included in each submittal.

2.3 System Design Features

2.3.1 General Design Concept

A central air-conditioning system shall be provided for the entire S/S., consisting of the following systems:

One central A/C-System with 2 x 100% (one working + one stand-by).

One central A/C-System with 3 x 50% (two working + one stand-by).

Separate Ventilation Systems with 3 x 50% (two working + one stand-by).

Separate Exhaust Systems with 2 x 100% (one working + one stand-by).

Each system shall be complete in every respect for a trouble free operation, including AHUs, fans, pumps, expansion units, ducting, refrigerant and drain piping, thermal and vapor insulation for ducts and pipes, sun protection shields for outdoor installed equipment, grilles, registers, diffusers, louvers, dampers, sound attenuators, vibration isolators, air coolers, electric air heaters, air filters etc.



The air handling units of the central air-conditioning system shall be located in a separate room to be integrated into the building.

The outdoor air in Abu Dhabi is often very humid and extremely corrosive due to the salt laden air carried by the wind from the open sea to the site. Therefore, all outdoor installed metal parts shall be made of appropriate material and given with anti-corrosive finish, in particular, the fan’s casing and wheel, the shaft and motor base, the housing and the perforated cover sheet of the splitters of the sound attenuators, the mounting hangers, supports, brackets, bolts, washers, nuts, etc. and the sand trap louvers, the weather protection louvers, the mounting frames and the unit frames, the outdoor installed air ducts, dampers and accessories.

The fresh air louvers, extract air louvers and extract fans installed on external walls shall be evenly sized, leveled and distributed considering the aesthetic view.

The fixing of grilles, diffusers, louvers etc. shall be concealed type as far as possible.

The use of wood or wooden frames is not acceptable, if unavoidable the wood/wooden frames shall be fully laminated with 1.0 mm aluminum sheet or painted with approved fire retardant paint.

2.3.2 HVAC-System for the Control, Electronic and Communication Rooms and related Areas

The HVAC-System shall consist of 2 AHU and 2 ACCU each designed to cover 100% of the cooling load, one on duty and one in stand-by mode as shown on the attached typical schematic air flow diagram.

Change-over shall be done automatically for the related fans and the motorized dampers, initiated by duct mounted differential pressure switches.

The AHU shall comprise the high efficiency air filter bank, the evaporative air cooling coil with drip eliminator (if required) and the S/A-fan and the motorized dampers.

If the air humidity is too high or if the room air temperature is too low the related duct mounted electric air re-heater shall be operated to increase the air temperature and to reduce the relative air humidity.

Upon sensing a higher RH% in the common return air, the central humidity sensor installed in the R/A-duct shall activate the Dehumidification coil (i.e. the cooling coil). Due to this a reduction in the room temperature also occurs which is not desired. This will be compensated by the operation of the Reheater installed in the S/A-ducts (step control with at least 3 steps). The air temperature shall be controlled by a central air temperature sensor installed in the R/A-duct acting on the ACCU (step control with at least 3 steps).



A high supply air temperature sensor shall be provided at the SA duct of the AHU (but before the duct heater) to create fault alarm and caution on the failure of the cooling fuction of the system.

2.3.3 HVAC-System for the Switch-Gear Halls and Related Areas

The HVAC-System shall consist of 3 AHU and 3 ACCU each designed to cover 50% of the cooling load, two on duty and one in stand-by mode as shown on the attached typical schematic air flow diagram.

Change-over shall be made automatically by motorized dampers, initiated after receipt of the remote alarm released by the safety thermostat installed in the R/A-duct.

The AHU shall comprise the high efficiency air filter bank, the evaporative air cooling coil with drip eliminator and the S/A-fan and the motorized damper.

The air temperature shall be controlled by a central air temperature sensor installed in the R/A-duct acting on the ACCU (step control with at least 3 steps).

2.3.4 Ventilation System for the Indoor Power Transformer Boxes

The indoor power transformers (if applicable) shall be ventilated as follows:

Each transformer bay shall be equipped with 3 x 50% redundant exhaust fans, sound attenuators and facade louvers with sand trap elements. All metal parts of the ventilation system shall be made of corrosion resistant quality.

Under normal operating conditions two fans shall be run simultaneously in parallel, so - if one of them fails - there will always be an active capacity of 100% available when referred to the full force nameplate rating of the transformer.

For a heat load of 210 kW from each power transformer, for example, each exhaust fan shall remove 26,500 m3/h of heated air from the transformer box at full speed in parallel operating condition when applying a temperature rise of 15 K.

The fans shall have two-speed motors (750/1500 rpm) designed to operate in an ambient temperature between +5oC and +65oC. Their speed shall be controlled by a temperature controller with a temperature sensor installed below the ceiling of the transformer bay.

There shall be in addition an alarm thermostat installed in each transformer box to monitor the function of the temperature control system and of the ventilation system.

Each fan shall be equipped with a motor driven damper to be automatically closed by an actuator, which includes an electric actuator and a spring drive. The damper motor shall be designed to operate in an ambient temperature of up to 65oC and in a humid and extremely corrosive salt laden air.



The function of each fan shall be controlled and monitored by a pressure differential switch to be installed downstream of each fan (including time delay relay for the start phase of the fan) to start the operation of the stand-by fan automatically if the supervised fan fails.

The noise of the fans shall be absorbed by sound attenuators to be installed upstream and downstream of each fan. The fan’s noise shall be reduced at 250 Hz by 33 dB (A) by the absorptive duct splitters. The effective air velocity shall not exceed 10 m/s between the splitters of the attenuator (max. 65 Pa pressure drop).

The outdoor make-up air shall be drawn-in into the transformer box by the low pressure (generated by the fans) through the vertically arranged sand trap louvers in the facade of the transformer box installed on grade level.

The sand trap louvers shall be designed for a nominal air intake velocity of 1.5 m/s at maximum as its air flow resistance is very high (about 65 Pa). This requires a facade opening of 5.4 x 1.8 m for each transformer bay if the heat load of each unit is 210 kW for example (2 x 26,500 m3/h).

The air exhaust openings shall get similar weather protection louvers as the air intake louvers but with horizontal front deflection vanes installed at ceiling level in the front facade of the transformer bay. The deflection vanes shall guide the air in a 45o angle upwards.

The weather protection louver shall be designed for an air exit velocity of 3.5 m/s at maximum as its air flow resistance is very high (about 55 Pa). This requires a facade opening of 5.4 x 1.2 m for each transformer box if the heat load of each unit is 210 kW for example (3 x 26,500 m3/h).

Access and maintenance facility for these exhaust fans shall be provided with the help of cage ladder and steel structured platform. The details of same shall be submitted separately for approval.

2.3.5 Ventilation System for Cable Floors, Basements and Cable Tunnels

Cable Floors/Basements and Cable Trench/Tunnels/Galleries shall be equipped with Twin Type (2 x 100% redundant capacity and equipment) extract fans for 4 (four) air changes per hour capacity with automatic change-over capability. Such rooms/zones shall also be equipped with suitable air inlet louvers, filters, duct works, grilles, extract louvers, dampers, etc.

2.3.6 Exhaust System for the CO2-Gas Flooded Rooms

Each air-conditioned room having CO2-gas flooding system shall be equipped with a separate roof mounted extract fan for 4 air changes per hour capacity, to allow the extraction of released gas after extinguishing the fire, with parallel make-up air supply for compensation.

Non-air-conditioned/ventilated CO2-gas flooded rooms/area shall be equipped with twin type (2 x 100% (one working + one stand-by) capacity and equipment) extract fans with automatic



change-over capability. Under normal conditions the system shall work for ventilation as usual. After receiving the local fire alarm signal, the fan shall be stopped automatically and the dampers shall be securely closed. The fan shall be restarted only manually for the CO2-gas extraction after the fire will be extinguished. As the CO2-gas is heavier than air it shall be extracted from the floor level of the room.

Such CO2-gas flooded rooms/areas shall also be equipped with suitable air inlet external louvers, duct works, grilles, extract louvers, motorized fire dampers which shall open automatically when the extract fan operates. Under normal conditions these dampers shall be securely closed in order to prevent disturbances to the air-conditioning/ventilation system. Adequate number of perforated floor panels shall be provided in rooms having false floors to allow transfer of CO2

gas and to allow transfer of extract air during extraction.

2.3.7 HVAC-System for the Battery Room

The battery room shall be air conditioned by the central a/c–plant and exhausted by 2 x 100% (one working + one stand-by) roof mounted extract fans with automatic change-over function, including air ducts, grilles, registers and valves. All ventilation equipment shall be made of acid resistant plastic material or made of plastic coated sheet steel if lead acid batteries are used. The fans isolators, switches, etc used for battery rooms shall be explosion proof when the batteries are of Ni-cad type.

It should be noted that the minimum extract flow rate recommended by battery manufacturer will prevail over the calculated AC supply air if the former is higher. In such case the AC supply air shall be increased in the calculation. But the supply air shall be 5% less than extract to maintain slight negative pressure.

2.3.8 HVAC-System for the Social and Sanitary Rooms

The toilets, shower and tea-kitchen rooms shall be air conditioned by the central a/c–plant and exhausted by 2 x 100% (one working + one stand-by) extract fans with automatic change-over function, including air ducts, grilles, registers, valves, diffusers, dampers and sound attenuators.

Other toilets, showers, kitchens, canteens, workshops and stores, located apart from the main building shall be air conditioned and ventilated as directed by ADDC/AADC.

Duct and pipe risers shall be covered by masonry enclosure with inspection and cleaning openings including removable cover plates of stainless steel and tile finishing.

Potable water supply pipes with tap and hose connection and suitable power point shall be provided close to the AHUs/CUs.

All staircases shall be over pressurized through fans with duct work, diffusers, external louvers and motorized dampers. The fans shall start automatically in case of fire.



2.3.9 HVAC-System for Fire Pump Room

Air-conditioning of Fire Pump Room shall be done as described above under Article: 2.2.3. During operation of Diesel Engine/Pump, Ventilation (fresh air and exhaust) shall be provided according to requirement/recommendation of Diesel Engine manufaturer, which shall work automatically during operation of Diesel Engine/Pump only, otherwise performance of Air-conditioning System will be badly affected.

2.4 Equipment and Materials

2.4.1 Air Cooled Condensing Units (ACCU)

Air cooled condensing units with casing construction made of galvanized sheet metal with 2 layers of an appropriate primer and an epoxy resin finish of 120 m -6 thicknesses. Only semi-hermetic reciprocating piston type compressors with built-in suction gas cooled motor and with integrated capacity control system shall be applied for high efficiency and safe operation.

Contractor may select and propose Condenser Units with Scroll Compressors in place of Reciprocating Compressors subject to compliance as under :

Provide one spare compressor for each three or less installed Compressors.

Five (5) years (supported by a bank guarantee) warranty for the Scroll Compressor beginning from the date of issue of PAC (provisional acceptance certificate). The compressor has to be completely replaced by a new one and free of charge if it has been found defective during this period.

Condensing units shall be equipped with oil filter, sight glass, replaceable core type filter-drier unit, expansion and safety valves and liquid line solenoid valves.

Condenser coils shall be made of copper tubes with copper fins and especially coated for corrosion protection by plastic coating, as e. g. Heresite, or equivalent.

Each ACCU shall be mounted on vibration isolation device under the base frame.

All components shall be protected from weather, heat, sun radiation, sand-storms and salt bearing air. Units shall be complete with refrigerant piping for the connection of the condensing unit and the AHU. Each ACCU shall have its own HP, LP and oil pressure gauges with isolating valves.

The unit control panel shall have all necessary safety and control devices for automatic operation under high ambient temperatures of up to 50oC and shall be protected from sun radiation by a sun shed.

Each condensing unit shall have a weather proof local isolator switch with a sun shed and more than one completely separated compressor and refrigeration circuits.



2.4.2 Air Handling Units (AHU)

Air-handling units shall consist of a double skin casing construction with top supply and return connections and hinged access panels with minimum 35 mm panel insulation and external plastic plating, a unit base frame made from galvanized sectional steel with 2 layers of an appropriate primer and an epoxy resin finish of 120 m-6 thickness, flexible supply and return connections, high efficiency bag filters with galvanised steel unit frame for the filter elements, plus washable synthetic air pre-filters with stainless steel unit frame for the filter elements, access doors and interior lighting by marine type lamps and all necessary safety, pressure difference monitor and automatic control devices.

The AHU shall include the centrifugal fan with spiral casing made from continuously welded and completely galvanized sheet steel with 2 layers of an appropriate primer and an epoxy resin finish of 120 m-6 thickness, including the impeller with backward curved blades for high efficiency made from continuously welded and completely galvanized sheet steel with 2 layers of an appropriate primer and an epoxy resin finish of 120 m-6 thickness, statically and dynamically balanced, shaft made of smooth polished stainless steel with bearing blocks and designed for a theoretical service life time of more than 40,000 operating hours in maintenance free and silent roller bearings with insulating gaskets and permanent lubrication, mounted on a common base frame for the fan casing and the motor, equipped with a V-belt drive consisting at least of 2 endless-type V-belts and designed for a trouble free start-up and steady operation even if one of the belts is broken, an electric motor designed for the maximum ambient condition and for the maximum power consumption of the fan including 10% power reserve at minimum, including stainless steel slide rails with stainless steel clamping devices and adjustable stainless steel belt tightening, a belt guard consisting of an easy accessible and removable protective casing made of reinforced and stiffened perforated stainless sheet steel, and combined with flexible duct connections spring or rubber type anti-vibration mountings, a copper drain device and copper wire-mesh guards at the intake-air cones of the fan’s casing. The evaporator shall be made of copper tubes with aluminium fins altogether fully tin plated against corrosion and drained by a stainless steel drip water pan and a plastic water trap with floating ball valve and a drain connection pipe. The evaporator shall include the electronic expansion valve, all refrigerant piping, thermal insulation with sun radiation and mechanical protection sheeting.

The refrigerant charge and all insulation material must be free of chlorinated components.

2.4.3 Refrigeration Piping

All refrigerant pipes shall be made of copper, type "L" according to ASTM B88-96 in straight length and including the matching fittings.

Refrigerant pipes shall be installed on heavy duty (galvanized and epoxy coated for out-door installation) trays and ladders supported at every 1.0 meter.



Cross over steps made from galvanized and epoxy coated steel frames and checkered plates shall be provided wherever required.

2.4.4 Condense Water Drain Pipes

All condense water drain pipes shall be made of copper, type "L" according to ASTM B88-96 in straight length including the matching fittings, water traps and with access openings for cleaning.

Cross over steps made from galvanized and epoxy coated steel frames and checkered plates shall be provided wherever required.

Indoor installed condense water drain pipes shall be insulated with minimum12 mm thick closed cell foam rubber insulation and shall be claded with 0.80 mm galvanized steel sheeting.

2.4.5 Refrigerant Pipe Insulation

Indoor and outdoor installed refrigeration pipe shall be insulated with minimum 19 mm thick closed cell foam rubber insulation with vapor sealing (cloth, foster) and shall be covered with 0.80 mm aluminum sheeting.

2.4.6 Air Extract/Exhaust Fans (E.F.)

Extract/exhaust fans shall consist of aluminum or GI casing, cadmium plated fixing bolts, dynamically balanced fan wheel made of aluminum, built-in local weather proof isolator switch, flexible connections, resilient mountings, easily removable access cover, air operated shutter, bird guard, motor with sealed-for-life bearing, directly driven by motor, necessary safety and control devices for automatic operation.

All the twin fans shall have automatic switch-over control in the event of fan failure, and manual/duty selector switches with run and trip indicator lights.

The construction and components of battery room extract fans shall be suitable to withstand all the conditions of acid vapor and corrosion.

All the extract/exhaust air fans shall be roof top mounted.

2.4.7 Electric Air Re-Heaters (EH)

Electric air re-heaters shall be provided in the main S/A-ducts for air heating and humidity control. The requirements of the humidity control shall override all the other requirements.

The electric heating elements shall be arranged in 3 equally sized heating banks to form 3 separate heating steps for an adequate control sequence.



The electric heaters shall consist of flanged frames with removable heater sections, finned tubular heating elements, manual reset thermal cut-outs, automatic thermal cut-outs, air flow switches, magnetic contactors, disconnect switch interlocks with terminal box covers, pilot lights, terminal boxes, stage contactors, fuses, step controllers, remote temperature and humidity sensors and controllers.

The casing of electric heater shall be manufactured from galvanized steel. The heating elements shall consist of 80/20 nickel chrome resistance wire centered in a metal tube and filled with magnesium oxide.

The frame of electric heaters shall exactly match with the frame of the duct connection and all the joints shall be airtight.

The setting values of manual cut-out, automatic cut-out and air flow switch shall be identified in submittal.

2.4.8 Air Outlets and Air Inlets (Registers, Grilles, Diffusers and Valves)

Air outlets and air inlets shall be manufactured from high quality anodized extruded aluminum sections with non-visible and mitered corners and joints with sponge rubber gaskets behind the frame and nylon bushings at the blade connection to the frame. Air outlets and air inlets for battery room shall be epoxy coated.

Air outlets and air inlets for other fixing surfaces shall have natural satin finish.

All the air outlets and air inlets shall be selected for their particular application and quiet operation.

2.4.8.1 Supply Air Registers (SAR)

SAR shall be with double deflection blades, having horizontal blades at front and vertical blades at back, fitted with key operated opposed blade dampers for air flow adjustment.

2.4.8.2 Return Air Registers (RAR)

RAR shall be similar to the SAR.

2.4.8.3 Supply Air Grilles (SAG)

SAG without blade dampers for air flow adjustment are not permitted.

2.4.8.4 Return Air Grilles (RAG)

RAG without blade dampers for air flow adjustment are not permitted.



2.4.8.5 Supply Air Diffuser (SAD)

SAD shall be supplied with hinged removable face and opposed blade dampers operated through an outside key for the rooms having false ceiling.

SAD for raised floors must be reinforced to walk on them and shall have perforated floor tiles.

2.4.8.6 Return Air Diffuser (RAD)

RAD shall be similar to SAD.

2.4.8.7 Exhaust Air Valves (EAV)

EAV with round air valve made of steel or plastic with white finish shall be used for toilets, showers and tea-kitchens.

2.4.8.8 Door Grilles (DG)

DG shall be non-visible type with "V" shaped inverted blades assembled horizontally, having a fixed frame on one side and a sliding frame on the other side.

2.4.8.9 Exhaust Air Grilles (EAG)

EAG shall have single horizontal fixed blade fitted with key operated opposed blade dampers for air flow adjustment.

2.4.9 Louvers

2.4.9.1 Outside Air Louvers (OAL)

OAL shall have sand trap louvers and air filters.

Sand trap louvers with vertically arranged profiled front elements shall separate the sand dust and dirt from the air stream. They shall be suitable to separate the heavy solid particles by the sand trap and 80% of the light particles by the air filter. Frame and main body of the sand trap louvers shall be made from galvanized sheet steel or 1.5mm thick aluminum sheet, which shall also contain an insect screen of stainless steel.

Air filters shall be made of 50 mm thick synthetic and washable filter mats with handle and filter rack made of stainless steel for easy removal.

2.4.9.2 Exhaust Air Louvers (EAL)

EAL shall be made from rigid extruded aluminum with inclined blades at 45o on 40 - 75 mm pitch to minimize water ingress. EAL shall also have insect screens of stainless steel.



Air outlets and air inlets to be fixed in false ceiling and/or on wall shall have a finish matching with the wall and false ceiling and coordinated with the architect for the color.

2.4.10 Air Dampers

2.4.10.1 Non Return Damper (NRD)

Non return dampers are not permitted and must be replaced by motorized dampers.

2.4.10.2 Volume Control Dampers (VCD)

All dampers affected by outdoor air shall be made from stainless steel, others may be made from galvanized steel, with aero-foil blades moving on 150 mm centers. The blades shall be mounted in stainless steel roller bearings to be operated by an exterior linkage.

VCDs shall have manual control with engraved quadrant position indicator, airtight lateral joint and air tight blades.

Sufficient number of VCDs shall be provided in the duct work in order to achieve the designed air distribution by proper air balancing.

2.4.10.3 Motorized Dampers (MD)

Motorized dampers shall be applied for all operating and stand-by AHU’s/Fans.

MD shall be same as the VCD but shall be equipped with an exterior electric drive motor including electric limit position switch for remote control and indication.

2.4.10.4 Motorised Fire Dampers (MFD)

The casing and other parts of the MFD shall be made from galvanized sheet steel, the blade axle shall be made of stainless steel and the bushing made of bronze. The isolating blade shall be made from asbestos free insulating material. The length of the casing shall suit the thickness of the wall or the floor slab.

The MFD shall have a fusible link (with 72oC release temperature), with spring return actuator and an electric limit switch for automatic remote indication.

The fire dampers shall be motorized and interconnected with the building fire alarm panel to close by spring return activation on de-energization of power supply. The MFDs shall be tested. On restoration of power, the activator motor shall re-open the damper and shall simultaneously prime the spring release.



2.4.11 Access Doors (AD)

Access doors on air ducts shall be hinge type with insulated double skin and air tight made from minimum 1.5 mm thick galvanized sheet steel and suitably stiffened, including handle operated lock.

2.4.12 Air Filters (AF)

The air filters shall be selected according to this specification and approved by ADDC/AADC. The air filters shall be bound with inner frames for locking filter media in place and sealing of edges to prevent air passing, but easily replaceable with all means of suitable access to the filters for proper maintenance such as ladders, walk-ways, railing, grating, access doors, etc.

All the filters shall meet the specified criteria of the "ASHREA" classification method.

The filter banks of the air-handling units shall be equipped with high efficiency bag filter insets and stainless steel mounting frames, including indicator instruments of approved type for easy reading of the air pressure difference over the filter bank and access doors. All outside air intakes shall be provided with stainless steel mounting frames and with washable synthetic air filter mats.

2.4.13 Sound Attenuators (SA)

Indoor installed sound attenuators shall consist of galvanized steel frame work, acoustic splitters and drilled angle flanges. Acoustic splitters shall incorporate the inert, rot and vermin-proof, non-hygroscopic and non-combustible mineral wool or glass fibber acoustic medium packed to a density of not less than 48 kg/m3 and retained by a perforated sheet steel facing.

The design and selection of the sound attenuators shall be made according to this specification and shall be verified by an approved calculation.

2.4.14 Anti Vibration Mountings

All dynamic machinery shall be isolated from the building structure by vibration isolators and/or vibration isolating materials, which shall be purpose designed and selected to suit the various machines.

2.4.14.1 Spring Mountings

Each mounting shall consist of cast telescopic top and bottom housing containing one or more helical springs of 50 mm minimum diameter, as the principal isolation elements. The mountings shall incorporate a built in leveling device and resilient inserts as guides for the upper and lower housing.



The bottom plate shall be fitted with a 6 mm thick neoprene pad bonded to it to reduce high frequency flanking. All spring mountings shall be designed such that the lateral spring stiffness is equal to vertical stiffness.

The mountings shall be selected for all items of plant with stiffness to cater for any eccentric weight distribution over the unit base. An equal static deflection shall be provided on all mountings to avoid the possibility of flanking caused by the plant tilting and rendering one or more of the mounts "solid".

Cage spring mountings shall be used for the packaged A/C units and air cooled condensing units according to manufacturer’s recommendations.

2.4.14.2 Resilient Hangers

All resilient hangers shall be of single element design with neoprene element or double element design with neoprene and helical spring elements. These elements shall be mounted in a steel cage pre-drilled and tapped at top and bottom to receive threaded hanger rods.

These hangers shall be used for duct mounted extract fans, fan coil units, pipes etc. and selection shall be made according to type/weight of equipment and manufacturer's recommendations.

2.4.14.3 Neoprene, Cork and Neoprene Pads

The pad shall consist either of a thick cork center-core between two neoprene pads (6 mm thick), and shall be used for floor mounted air-handling units, small (less than 5.0 refrigeration tons) condensing and package units, roof mounted extracts fans etc.

The selection of pads shall be made according to type/weight of equipment and manufacturer's recommendations.

2.4.14.4 Flexible Duct Connections

Flexible canvas connections with high temperature resistance shall be provided at all suction and discharge connections of fans, air-handling units and at duct work crossing the building expansion joint.

Flexible connections shall be factory fabricated from chemically impregnated canvas. The flexible connections shall be securely fixed/clamped to duct work and equipment in an air tight fashion.

The unclamped section of flexible connection between equipment and duct work shall not be less than 100mm.



2.5 A/C Control System and Control Panels

2.5.1 General

The centralized electrical power supply and the control panels of the HVAC-System shall be provided in the same room where the AHU is placed.

Concerning A/C Control Panel requirements, reference shall be made to Standard Technical Specification, Part:

S-AA-CUB - Cubicles and Enclosures

Fan motors and compressor motors must have a local isolator switch for a secured service and maintenance work.

2.5.2 Motor Control Cubicles

Floor mounted panels shall have die cast metal construction, enclosed at all sides with lockable front door and rubber packing, mounting frames or plates for equipment at rear, hammer faced texture painted. Panels shall be wired up to the labeled water repellent and non tracking terminal blocks, wiring in the cable trunks with insulated fixed neutral bar, 20% spare terminals and installation place have to be provided.

Concerning Motor Control Cubicles, reference shall be made to Standard Technical Specification, Part:

S-AA-CUB - Cubicles and Enclosures

Operating pilot and indicating devices have to be situated in the front panel for easy reading. The panels shall be equipped with incoming and outgoing breakers. Each unit shall be switched on and off by means of push buttons / switches (with contactors) and their operation is to be indicated by signal lamps.

The cubicles and panels must be complete including cabling, wiring, terminal racks and earthing and must be protected according to IP54.

Wiring for different purposes must be supplied in different colored material to avoid errors and faults. The wiring shall be labeled and shall be easily legible.

2.5.3 Automatic Control System

A complete electronic micro-processor based automatic control system shall be provided, including, but not limited to the following:

Motor control cubicles and control panels including



Phase indicator lamps (R,Y,B)

Voltmeter with selector switch

Ammeter with selector switch

Main switch

Interior panel fluorescent light with door switch

Lamp test button

Anti condensation heaters and humidistat

Temperature and humidity sensors with each electric air re-heaters

Ventilation fan with filter for the A/C control panel

High temperature alarm for control/relay room, SCMS room, offices, etc.

High humidity indication for control/relay room and SCMS room open/close indication for each motorized and fire damper

Run/off/trip indication for each condensing unit, AHU, fan and heater

Air flow failure and common dirty filter alarms and run/trip/stage indication for each heater battery

Common fault alarm of each system on the HVAC panel

Interface facility of HVAC system to SCMS

Shut down of all HVAC equipments upon fire alarm with a separate Fire Alarm Tripped (fault) indication. This will exclude CO2 extract system fans and stair pressurization fans.

Control circuit on/off switch separate circuit breakers for extract fans, heaters separate circuit breaker/fuse for each damper

Fire alarm reset button

Duty selector switch for each AHU and fan

Hand/off/auto selector switch for each condensing unit, AHU and fan

Automatic change-over of air cooled condensing units due to HP, LP, OP, air flow failure, compressor failure, condensing fan failure, main fire damper closing, supply or return air damper closing or circuit breaker trip

Interlock of CO2-gas extract fan with fresh air make-up system and motorized fire dampers

Pressure switch for air filters



Controller receiving input signals and issuing control signals; set point, proportional band shall be adjustable in the controller with a hand held programmer for output/input programming

Transmitters with output signal installed at the measuring points

Air-conditioning control panel and all the components inside the panel shall have identification labels of approved type

Complete cabling, wiring, terminal racks and earthing.

3 SERVICE AND MAINTENANCE

The entire HVAC systems shall be maintained during the warrantee period to the satisfaction of ADDC/AADC. The Bidder/Contractor shall maintain the stock of necessary spare parts during this period and shall attend immediately the faults/break-downs reported by ADDC/AADC.

At the termination of the warrantee period, a final and approved maintenance program shall be done and ADDC/AADC shall be invited for inspection/acceptance.

4 OPERATION AND MAINTENANCE MANUALS

Operation and maintenance manual as hard copies as well as soft copies (as per contract) shall be submitted before starting the testing and commissioning at site and shall include, but not be limited to the following:

Description of HVAC system, its function and operation

HVAC arrangement and layout drawing

Air flow diagrams

Control schematics and single line diagrams

Terminal and wiring diagrams

List of manufacturers and suppliers with their addresses

Manufacturer’s operating and maintenance instructions

Service and maintenance schedules

Shop inspection and site test reports

Technical documents, which shall include the manufacturer’s literatures

List of specified spare parts, consumables and tools

List of as built drawings.



5 TESTING, ADJUSTING AND BALANCING

5.1 General

On completion of the entire mechanical installation work or any separate system or distinct part thereof, the Bidder/Contractor shall notify ADDC/AADC, in writing, that the completed part of the mechanical work is ready for inspection. Before doing so, perform initial trial tests, and correct, adjust, calibrate, balance, regulate, and alike, the system concerned as necessary until the specified and required performance conditions are obtained.

The inspection of the contract work shall be carried out by ADDC/AADC in accordance with the requirements of the ASHRAE and NFPA commissioning standards.

The operation tests of various systems shall be as specified separately in each concerned section of this specification. The results and readings obtained shall be equal or better than the requirements of the specified and approved data and these shall be recorded on forms approved by ADDC/AADC.

The Bidder/Contractor shall supply all labor, materials, instruments, tools and equipment required for carrying out the tests.

When equipment or services of a specialized nature are involved, the Bidder/Contractor shall provide the services of a specialist from the manufacturer who shall be present at the time of testing and commissioning of their equipment. Further the Bidder/Contractor shall provide the services of an approved, independent testing authority for Testing and Commissioning of HVAC System. All expenses incurred in this respect shall be included in the Contract as no claim for additional payment will be entertained.

The Bidder/Contractor shall submit to ADDC/AADC the test reports, which shall include all records of test procedures, readings and results obtained.

5.2 Approval by Public Authorities

The Bidder/Contractor shall ensure that, where applicable, the work and any materials used in the execution of the work is in accordance with the Contract and complies with the requirements of the particular Public Authority having jurisdiction.

Where necessary to comply with public regulations, the Bidder/Contractor shall inform the Public Authority of the proposed work and obtain from them any written approval that may be required.

The Bidder/Contractor shall submit to the Public Authority any materials for testing that the Authority may require. He shall provide ADDC/AADC with a copy of all correspondence, test certificates, and alike, in connection with the works.



5.3 Job Conditions

The Bidder/Contractor shall not proceed with testing, adjusting, and balancing work until work has been completed and is operable. He has to ensure that there is no latent residual work still to be completed, and the system has been started-up.

5.4 System Test Start-Up

The system test start-up shall include the following:

All equipment shall be operable in safe and normal conditions

Temperature control systems shall be complete and operable

The thermal overload protection shall be in place for the electrical equipment

All final air filters shall be clean and in place. If conditions warrant, the Bidder/Contractor shall install temporary media in addition to the final filters

All fans and duct systems shall be clean of debris

The fan’s rotation shall be correct

Fire and volume dampers shall be in place and open

All coil fins shall be cleaned and combed

Access doors shall be closed and duct and caps in place

All air outlets shall be installed and connected

Duct systems leakage shall not exceed the rate specified.

5.5 Functional and Performance Tests

5.5.1 Test of the Air Systems

Thermostats setting adjustment shall be tested with the air heaters and air coolers

The performance of the unitary DX air-handling units and the electric duct-heaters shall be checked. After adjustments at supply and return air systems are made, the following items shall be re-checked and re-adjusted if required

Compressor full load amperes (for each compressor)

Blower RPM and motor full load amperes

Condenser motor full load amperes



System static pressures, both at suction and discharge

System re-circulated air and outdoor air, DB & WB temperatures

Air flow pattern shall be tested for freedom from draughts during a heating period, and during a cooling period in the occupied areas by means of an air flow tester

Room inside conditions (for each room) DB & WB temperatures should be checked and recorded

The automatic back-draft dampers at roof fans and the operation of damper positioning motors shall be tested

The manual switches and the main disconnection switches external to the main air-distribution and extraction equipment shall be tested together with the associated operation and fault lamps

The automatic controls shall be tested individually for satisfactory operation.

5.5.2 Sound Test

The tests shall demonstrate the compliance with the sound level requirements and shall be conducted in selected areas of the buildings. Readings shall be measured in decibels on the "A" scale of an approved sound level meter.

Readings shall set forth the total random sound level of the selected area with the system in operation as compared to total background sound level with the system not in operation.

If sound levels are above the specified levels, adjustments shall be made to bring the sound level within the range. If this cannot be done with the equipment as installed, recommendation shall be made to correct the sound level to within the specified range.

Sound level readings shall be taken at the air diffusers grilles, or registers, approximately 1.5 meters above the floor, on a line approximately 45 degrees to the center of diffusers, grilles or registers.

5.5.3 Reliability Tests

After satisfactory completion of the total system balance, the Bidder/Contractor shall be responsible for running reliability tests for all plant and equipment.

Each reliability test shall last for a period of 6 consecutive days during which time the whole of the plant under test shall operate continuously without adjustment or repair to the satisfaction of ADDC/AADC. In the event of any repair or adjustment having to be made other than the normal running adjustment, the test shall be void and the installation shall be re-tested after the re-adjustments or repairs have been completed.



A Test shall not be void due to circumstances outside the control of the Bidder/Contractor.

The reliability tests of the refrigeration and air cooling system shall take place during the period between 15th of June and 15th of September and for the air heating system during the period between 1st of December and 28th of February.

All log sheets for recording the test results shall be prepared by the Bidder/Contractor and approved by ADDC/AADC. Daily log sheets duly filled in shall be submitted to ADDC/AADC the following day for review and approval.

Temperature and Humidity recorders shall be used for sensitive areas as selected by ADDC/AADC for continuous recording of these parameters.
