Sustainability Program for Community Housing Organisations Compass Housing Services This project has been assisted by the New South Wales Government through.

Sustainability Program for Community Housing Organisations

Compass Housing Services

This project has been assisted by the New South Wales Government through its Energy Efficiency Training Program

Copyright and disclaimer The Office of Environment and Heritage and the State of NSW are pleased to allow this material to be used, reproduced and adapted, provided the meaning is unchanged and its source, publisher and authorship are acknowledged. The Office of Environment and Heritage has made all reasonable effort to ensure that the contents of this

document are factual and free of error. However, the State of NSW and the Office of Environment and Heritage shall not be liable for any damage which may occur in relation to any person taking action or not on the basis of this document. Office of Environment and Heritage, Department of Premier and CabinetPhone: (02) 9995 5000 (switchboard)Email: [email protected]: www.environment.nsw.gov.au

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Thermal performance

• How energy comes into, around and out of our homes

• Maintaining interior comfort levels

• How behaviour can heavily influence energy and cost

• Largely determined by building design

• 78 images

Achieving thermal comfort

Thermal comfort is achieved by having your body in equilibrium- the heat coming onto the body matches the heat leaving the body.

Thermal comfort is subjectivePeople feel heat differentlyGenerally, People from the UK find the climate here very warm – hotPeople from the equatorial countries- i.e. Singapore generally find climate here cool.

How we are conditioned can have a big effect on heating or cooling costs.

Heating and cooling expectations are now much greater then they used to be.

Heat Movement

It is important to understand the 4 methods of heat transfer.•Radiation. Heat transfer through space, and heating only the object that catches the radiation •Convection. The movement of air due to the fact that warm air is lighter than cool air. •Conduction. Heat transfer through direct contact between warm and cool objects.

Evaporation

The other major method of heat exchange,•It is extremely effective at cooling•Water absorbs a very large amount of heat (2.3MJ/litre)or .6KWh/l

That is why•Sweating is so effective, •Breezes are so refreshing in summer.

Evaporation depends on lower levels of humidity.•That is why evaporative air conditioners are common inland•But not along the relatively humid coastal strip.

Passive solar design-What is it???

A method of controlling the internal temperature of a building by using appropriate design principles.

Features of passive design?•Creates comfortable living conditions while avoiding the use of expensive appliances for heating and cooling•Free heating from the sun during winter•Shielding house from sun in summer keeping it cool•Makes use of the cooling breezes in summer •Passive because the house design self regulates temperature

•The best results are gained by active occupants

Seasonal variation of the Suns path

Ideally a long face of the building faces north for maximum solar control•Note shadow length and angle of sun. •Many streets-full of existing houses are already orientated the right way, and are relatively easily adapted.

Passive solar design

….. the major featuresImage: Yourhome.gov.au

Thermal mass- examples

MATERIAL THERMAL MASS(volumetric heat capacity, KJ/m³.k)

Water 4186

Concrete 2060

Sandstone 1800

Compressed earth blocks 1740

Rammed earth 1673

FC sheet (compressed) 1530

Brick 1360

Earth wall (adobe) 1300

AAC 550

Source: EDG

Eaves and solar control

http://www.yourhome.gov.au/technical/fs45.html

Essential features for passive solar function

• Correct orientation of windows -for allowing or rejecting solar heat. (Mostly on north side)

• Ventilation for summer cooling• Thermal Mass for storing heat or cool• Insulation to resist heat flow- in , or out• Shading by eaves and vegetation -sun control

Reverse Brick VeneerReverse brick- veneer is a perfect building system to use in mixed climate zones.A mixed climate zone is where it is often too hot in the summer, and too cold in the winter i.e. most of southern Australia.

General Layout priorities

• East– west orientation, with long face either front or back• Living rooms toward the north side• Lesser used rooms to the south- • More windows to the north, easy solar control• Less windows to the W, E, and least to the south.

Credit: yourhome

Design example- Every room has solar access

North

• Large windows along north face• Thermal mass along front for heat control• Windows allow breezes• With good insulation, energy bills close to ZERO for heating and cooling

Credit: Ian Garradd, Madhan Sekar

Site analysis and solar potential zero energy home. -A feasibility study, Tasmania.

• All energy and water could come from the building

Images: Ian Garradd

Eventually all buildings are likely to be carbon neutral in their operation

Images: Henley Homes, Delfin, Lend -Lease

This is one recently built in Melbourne by some progressive developers. …It looks just the same as any other well- designed home.

Compass north is not true north

The best orientation for passive solar design is TRUE north, or GRID north, often referred to as SOLAR north

Credit: Google earthCredit: yourhome

Does it apply to existing buildings?

While in practice, we will be mostly dealing with existing housing, it is essential to be familiar with the major elements of natural heating and cooling….

•as it is possible to adapt most buildings to harness at least some of the free heating and cooling potential.

•It is important to consider passive solar energy potential when either buying , or renting a house, as it will have a large impact on the cost of living of the occupant$.

Building energy ratings to come

• Indications of energy required to keep house interiors comfortable• The A.C.T. has been using mandatory energy ratings since 1999

(in the ACT)

National home energy ratings

What the stars mean

•Zero stars means the building shell does practically nothing to reduce the discomfort of hot or cold weather.

•A 5 star rating indicates good, but not outstanding, thermal performance.

•Occupants of a 10 star home are unlikely to need any artificial cooling or heating.

What effect do various design features affect energy and thermal

comfort?

Credit: Ian Garradd

Energy from the sun

• Summer sun radiation approx. 1000 watts/ m2• That’s why you want to bock it out

• Winter sun approx. 500 watts / m2• That’s why you want to let it in

Houses will be more comfortable if we make the most of what nature can offer

“It seems to me that we all look at Nature too much, and live with her too little.”Oscar Wilde, "De Profundis", 1905

Sun control begins in the garden

• The trees provide a HUGE benefit for summer cooling• Keep north windows unshaded to allow winter sun into windows• More comfortable interiors, cheaper to run

Credit: Ian Garradd

Thermal mass• Heavy, massive materials have large heat capacity. • Internally, they can retain very useful warmth, or coolth.• Exposed, i.e. not carpeted surfaces are best- i.e. tiles, brick, etc.

• Thermal mass inside a house reduces daily

temperature fluctuation

Summer

Winter

Credit: yourhome

Design features for summer comfort

Street frontage faces north, season- mid summer

• Large north facing windows with wide northern eaves• Keeps the summer sun out, but lets the winter sun in.• What effect will happen on the west windows/ wall in pm?

Roof colours

• White coloured roofing is around 30 degrees cooler than dark • Where is a large part of the heat going to end up?• Reliance on air conditioning?

Trees for cooling

1. Trees are essential for controlling temperature in and around the home

2. The yard is far more pleasant with the cooling effect of trees3. An extremely low cost solution for summer cooling 4. If tank water is available, put the sprinkler through the leaveson for free air conditioning

Image: yourhome.gov.au

Keep the sun off the glass in summer

If glass gets hot, heat is already heading inside•External shading is far better than internal shading – blinds, etc.•External shutters•External awnings•External roller blinds

East facing house

Comparison of heat gains through different window treatments

Image: Sustainability Victoria

Awnings

• Best for east or west walls• Ensure a heat-reflective fabric

is specified• Leave up in winter to let

winter heat in• Needs occupant motivation

to control it• Awning should extend

beyond window frame , i.e. approx. 300 mm each side

Image: Ian Garradd

Insulated and lined verandas

• A verandah, eave, or awning with insulation transmits negligible heat.

• This will heavily impact on interior temperatures, as much of the heat which comes through as radiation goes through the walls and windows to the interior.

Image: Ian Garradd

Reflective foil insulation

2 main categories of insulation….Reflective foil is most suited to keeping heat out in summerThick blanket insulation is for keeping heat inside They are both essential for year –round comfort

• Generally put under sheeting and tiles but retrofitting easier under rafters.

• A more effective and safer method of retrofitting foil (just a bit more effort)

Night purging and breezes

Methods of achieving air movement in a house.

sealable high wall vents

roof ventilator

ceiling fan

closable inlet vent for exhaust fan

exhaust fan

fully openable window area

openings on opposite sides

of house

closable inlet vent for roof ventilator

minimal obstructions between openings

• Landscaping to direct cooling breezes

• Allow cross- ventilation to do most of the cooling with sea breezes, or night breezes

• Requires vigilance

Image: yourhome.gov.au

Be familiar with useful breezes

Wind roses showing local summer breezes at 9am and 3pmStrong afternoon cooling breezes from the East and South-East

Security screens • Security screens essential

in many cases so that people can relax while leaving doors and windows open for summer cooling.

The Stack Effect for summer cooling

• Allows warm air to leave the house by convection

• Open windows and doors in summer

• Operable skylights are also excellent for this

Image: US dept. of housing

Cross–flow for most effective cooling

• In the front door and out the back,

• Or open whatever combination of windows and doors can achieve air flow through most of the house, or warm rooms.

The more breeze options the better.

Whirlybirds

Exercise:200 m2 dark roof tiles….

•Calculate the load at any one time•How much difference will 1 whirlybird make?

Image: Ian GarraddImage: Nearmap.com

Maximise cooling potential for hot weather

Always use natural breezes instead of appliances to keep cool if possible

A better solution

• White roof, • Multiple industrial size whirlybirdsThis combination has a large impact on internal temperature

Image: Ian Garradd

Effective venting of warm air from interior

Operable skylights •Remove heat from ceiling level•Available with double glazing, thermal treatments, and blinds.•Highly effective and versatile

Image: Ian Garradd

Summer climate control review.

• Each person to recount an experience of an aspect of a home, where it was too hot.

• Explain what you would do about it - in hindsight• Summarise the main aspects of heat control.

Break 5 min