Cooling a Home

The hot summer months in Perth require attention on how we can cool our homes. The recent upsurge in use of domestic air-conditioners (either refrigerated or evaporative) is one way residents have dealt with the problem. However both the upfront and usage costs of mechanical cooling devices can be expensive. As an alternative there are many natural cooling methods which you can consider which are effective and inexpensive.

The best method to cool your home is to prevent heat build up in the first place. The main source of heat build-up is sunlight absorbed into the home through the roof, walls and windows. Secondary heat sources including heat generating appliances need also to be considered.

If you are building a new home, there are a few things to consider:

• Dark, dull coloured exterior surfaces absorb most of the sun’s radiant energy. Light coloured surfaces reflect the heat away. White or light cream brick, white paint, coloured sandstone etc all have good levels of reflectance, and will ultimately result in a cooler home;
• Window treatments such as sun control films are effective in controlling heat. Some of these treatments are tinted which can also reduce the amount of light in a room;
• Block the heat through roof and/or wall insulation and effective shading. Roof insulation should be a minimum of R.2.5 rating. Pay particular attention to landscaping, including the planting of deciduous trees, and other vegetation which can offer plenty of natural shade;
• Exterior shading devices such as awnings, sails, solar screens and shutters are very effective in blocking direct sunlight. Appropriate curtains, pelmets and venetian blinds are interior devices which are also very effective in blocking sun and heat;
• Natural ventilation is effective in keeping indoor air temperature equal to the outdoor temperature and reducing the amount of accumulated heat. Pay attention to the orientation of your home, and window sizes to maximise the advantage of Perth’s sea breezes. Ceiling fans are another efficient device to supplement natural air flow in a new home. Of course if the outdoor temperature is higher than inside (usually in the hottest part of the day) keep doors and window treatments closed; and
• Often overlooked sources of interior heat gain in a home are lights and household appliances such as ovens, dishwashers and dryers. Fluorescent lamps emit less heat for the same amount of light. Check the energy efficiency rating of your new appliances and their heat generating capacity.

Good luck in keeping cool this summer.