Cool your home efficiently

Last updated: 6 September 2022

If you operate and maintain your cooling system wisely, you can reduce your cooling costs and still be comfortable. The best approach will depend on whether you have an air conditioner or evaporative cooler.

Air conditioners

Keep windows and doors closed

Keep them closed when the system is operating to avoid wasting energy.

Minimise the area to be cooled by zoning

  • Keep the area you are cooling to a minimum by closing doors to other rooms not requiring cooling.
  • Check your manual to see whether you can turn off some of the cooling outlets (where applicable) to reduce the area of your house that you are cooling at any one time.

Use the thermostat correctly

  • Set your air conditioner thermostat between 24°C and 26°C for living areas – every degree lower in summer will increase running costs by around 10%.
  • Place your thermostat for central cooling systems in living areas where you spend most of your time.
  • Protect your thermostat from draughts and heat sources such as heating outlets and direct sunlight.
  • Do not place thermostats on external walls.

Don't leave your air conditioner running

It is far cheaper to turn the air conditioner off while you are out or overnight while sleeping, and on again when you return or wake up in the morning. A fan will generally keep you comfortable during warmer nights and will cost far less to run. Use the economy setting if your system has one – this setting reduces energy use by maintaining moderate rather than cold temperatures.

Install a timer or programmable thermostat

At the hottest times of year, a timer allows you to turn your air conditioner on and off automatically, say 20–30 minutes before rising in the morning or getting home in the evening. For standard plug in air conditioners you can purchase a simple timer from your local hardware store to do the same job.

Turn the system off when you go on holiday

Don't forget to turn the entire system off completely when you go away on a holiday.

Keep and let in cool air

  • Close curtains and blinds to reduce heat gain through your windows, especially when the air conditioner is running.
  • External shading is more effective at keeping your home cool than internal blinds or curtains, but using both external and internal window coverings will provide maximum protection.
  • Turn the air conditioner off when the outside temperature drops, and open doors and windows to let the cool air in.

Shade the compressor unit

If the compressor unit (the part located outside) is exposed to full sun during the day, shade it with an awning, shade mesh or a similar structure. Be careful not to restrict air movement around the unit by keeping curtains and furniture clear of outlets.

Insulate your home

Insulating your home can save you up to 45% on your energy bills. Install insulation in your ceiling, walls and floors to create a sealed envelope which acts like a thermos in winter and an esky in summer.

Draught proof your home

Prevent loss of cool air generated by your cooling system by sealing gaps around doors and windows to draught-proof your home.

Consider fans

Use portable and ceiling fans wherever possible – they are much cheaper to run than air conditioners and can also be used in conjunction with your air conditioner to circulate cool air.

Maintain your air conditioner

  • Ensure any ducting is free of air leaks. Escaping cool air will cool your roof space instead of the inside of your home.
  • Clean air filters regularly.
  • Service all air conditioners and replace parts according to the manufacturer's instructions.

Evaporative coolers

Open doors and windows

Ensure that doors and windows are kept open in rooms being cooled, and that the opening is large enough to allow the air to flow freely outside. Having insufficient openings will reduce the cooling effectiveness of the unit and may put too much back pressure on the fan.

Open opposite doors and windows

Reduce heat gain by opening windows and doors on the opposite side of the house to the hot prevailing winds where possible.

Use your timer

If your unit has a timer, consider using it to switch the system off when cooling is not required, such as in the early hours of the morning.

Adjust for humidity

On days of high humidity, turn off the water supply to the cooler and run the fan only. This can be quite effective on still, humid evenings when the outside air has cooled down.

Prevent air leakage in winter

Ducted evaporative cooling outlets can be a significant source of heat loss in winter. Special covers are available which can be fitted over the outlets in winter to reduce heat loss through evaporative cooling outlets.

Maintain your evaporative cooler

Evaporative coolers should be regularly serviced and maintained in accordance with manufacturer's instructions to keep them operating effectively.


Fans are inexpensive to run and purchase

Ceiling or wall-mounted fans and portable electric fans can cost less than two cents per hour to run and can be inexpensive to purchase.

Use fans in conjunction with your cooling system

Although fans do not reduce the air temperature, when used in conjunction with your air conditioner or evaporative cooler they can reduce the need to use your cooling system.