Frequently asked questions
My house gets really hot in summer - how can I cool it?
Before purchasing a cooling system, there are many improvements that can be made around the house to make it naturally cooler in summer, including:
- Shading windows from the outside with eaves, external blinds and awnings (use vertical shades for east and west windows, and horizontal shading for northern windows) or trees.
- Shading windows on the inside with heavy curtains or blinds.
- Using reflective tints or toned glass in windows.
- Installing insulation - a well insulated home is up to 7°C cooler in summer.
- Ensuring adequate ventilation and good cross ventilation to naturally cool the house.
What is the best type of cooling system?
The best type of cooling system is a well designed and well oriented home that optimises natural breezes and shading. However, if extra cooling is required, the best system for you will depend on a number factors including climate, the size of the area you want to cool and to what degree.
Fans are the most energy efficient form of cooling. They are the cheapest to purchase, cheapest to run, operate quietly and are suitable for rooms of all sizes.
Evaporative coolers cool air by evaporating water into the air. They are generally not recommended east of the Dividing Range as they require low humidity to cool effectively..
Refrigerated air conditioners remove heat from the air inside the home and transfer this heat outside. Reverse cycle models also provide heating in winter. They have the highest running costs, and are therefore best suited to very hot climates where other cooling systems cannot provide the required comfort level.
I am getting ducted air conditioning installed, is there anything I can do to make sure it works effectively?
Consider the measures outlined in Question 1 above to reduce the amount of heat the air conditioner needs to remove from your home.
Ceiling fans will help to move warm/cool air back down to floor level in rooms with very high ceilings (e.g. cathedral ceilings).
What are variable speed compressors or inverter drives?
Variable speed compressors are a new technology that improves the efficiency of air conditioners.
Unfortunately the contribution of variable speed compressors (or inverter drives) is not well measured by the energy star rating. This rating is based on the maximum output, which may not necessarily be the operating output.
Therefore, an air conditioner with a 4-5 star rating and a variable speed compressor might outperform a 6 star rated machine without a variable compressor.
What is a heat pump cooling system?
All refrigerated air conditioning systems, including reverse cycle air conditioners, are heat pumps (so are refrigerators). A 'heat pump' transfers heat from one zone to another.
Heat pumps consist of an indoor and outdoor coil connected by a pipe through which a refrigerant circulates (note that refrigerants used are now CFC free). As warm air passes over the inside coil, heat from the air is absorbed by the refrigerant. This cools the air that is released back into the room. Meanwhile, the heat absorbed by the refrigerant is transferred to the external coil where it is released to the outside air.
Reverse cycle air conditioners also work in reverse to provide heating. During the heating mode, heat is absorbed from the outside air and transferred via the refrigerant to the air inside your home.
It doesn't have to be warm outside for reverse-cycle air conditioners to work - they are capable of providing adequate heat when outside temperatures are below freezing. Check with manufacturers for operating temperature ranges.
Page last updated: 27 February 2011
