Heating and cooling can account for about 40% of the energy used around your home. You can reduce the amount of energy you use by making a few simple and practical changes.

Simple steps to cool your home

You can use the right combination of cooling appliances, items in your home and our environment to help cool your home efficiently.

Shade and insulation

Keep out unwanted heat by shading north and west sides of your home. Adjustable external shading, seasonal trees and closing curtains and blinds will help keep your home cooler in summer, without permanently blocking the sun you need in winter.

Installing insulation in your ceiling and walls can significantly reduce the amount of heat transferred into your home.

In summer, an uninsulated house will gain most of its heat through the ceilings and windows. Uninsulated walls also contribute to heat gain, as well as air leaks around doors.

If your home gets too hot, the insulation will begin to keep the heat inside. Always try to keep your house shaded if using insulation, particularly the windows.

Insulation can deteriorate over time so make sure it’s replaced or topped up when it stops being effective. If you rent, ask the landlord to install it or top it up if it’s no longer effective.

Make sure your insulation installer has a South Australian builder’s licence that permits them to install insulation and ask them about the best R-value for your home and needs.

Make your cooling more effective

When using a refrigerative air conditioner, only cool the areas you need by:

  • closing internal doors
  • using the zone controls on a whole-of-house system.

Sealing gaps around doors and windows and using draught excluders will reduce wasted energy.

Evaporative air conditioners work differently and are more effective if you open some doors and windows to increase air flow.

Research your cooling system online or follow the manufacturers instructions to make sure you are using it effectively and efficiently.

If it's cooler outside at night, turn off your air conditioner and open doors and windows to allow cooler breezes in. You could use window locks or lockable screen doors to keep your home safe.

Household tips for cooling

Smaller, simpler steps can also help keep your home cooler in summer:

  • Switch off and avoid using unnecessary appliances, especially any that generate heat. For example, chargers, televisions, computers, and lights with warm bulbs.
  • Invest in house plants. They can improve air quality and add extra shade near windows. They can also absorb some heat.
  • Use lighter coloured materials around the house. Dark colours absorb more light and radiate it as heat. The same applies for your roof. So consider lighter colours when replacing or repainting it.
  • Remove floor rugs to expose cooler flooring, such as tiles and floorboards.
  • Make sure fans are switched to summer mode.
  • Keep your air conditioning vents and fans dust free so clean air can flow through.
  • Take actions during the middle of the day, so that you’re not trying to cool a hot house later in the day. For example, close blinds and curtains before the sun hits the window and heats the room. Consider using your air conditioner on a timer while you’re not home, to maintain a cooler house during the day.

Choosing cooling appliances

Knowing how much your appliance costs to run will help keep track of your energy costs. Use this information to help you select the best cooling appliance for your needs, and view the estimated hourly running cost for different tariffs and plans.

Cooling appliance types


Ceiling and portable fans are the cheapest type of cooling appliance to run. They create air movement that helps carry heat away from you and can help you feel cooler.

You can use fans at the same time as other cooling appliances to help move cool air around your home.

Evaporative coolers

Evaporative coolers use water and a fan to blow cool, humidified air into your home, and have very low running costs. They work well in dry weather but can be less effective when it’s humid.

Evaporative coolers need good ventilation so the cooled air can push the warm internal air outside. Portable coolers also need air flow to operate effectively, so position them near an open window or door.

Refrigerative air conditioners

Refrigerative air conditioners cool air to a set temperature by removing heat from the room. Reverse cycle systems can also heat in cold weather.

These systems can offer greater cooling, especially in humid or higher summer temperatures. But they usually cost more to run than evaporative coolers. You also need to shut windows and doors for them to work effectively.

The bigger the space you cool, the more energy you use and the higher your running costs will be. Closing doors to rooms you’re not using and using the zoning control on a whole-of-house system can reduce your cooling costs. For example, minimise cooling in unused bedrooms during the day and in the living room while everyone is sleeping at night.


You could be wasting energy and losing a lot of cool air if your ducted system and ducts are poor quality or have deteriorated, You can reduce that loss by sealing or insulating your ducts with the help of a qualified professional.

When purchasing a system or replacing ducting, look for an R-value of at least 1.5 for the ducting, and 0.6 for the fittings.

Running costs

Cooling appliance Hourly running costs Works best in Operating tips
Ceiling and portable fans

Flat rate

Time of Use
1–3c (shoulder)
1–3c (off-peak)
2–5c (peak)

Models available for all room sizes and spaces
  • Can be used on their own or with other cooling appliances.
  • Can help move cool natural breezes through your home.
  • Reversible ceiling fans can also help with winter heating.
Portable evaporative

Flat rate

Time of Use
4c (shoulder)
5c (off-peak)
7c (peak)

Rooms up to 20m2
  • Needs good air flow to operate effectively, so place near an open window or door
  • Additional 1–2c water costs per hour
Portable refrigerative

Flat rate

Time of Use
23–34c (shoulder)
26–40c (off-peak)
41–61c (peak)

Rooms up to 20m2
  • Not as energy efficient as split systems but more effective in well-insulated homes.
  • Includes indoor and outdoor components connected by a hose passed through a partially open window.
  • Setting the thermostat to 24–27oC or as high as is comfortable for you, will reduce running costs.
  • Direct louvres at the ceiling, as cold air falls.
Window and split refrigerative systems

Room up to 36m2

Flat rate

Time of Use
27–40c (shoulder)
32–46c (off-peak)
42–70c (peak)

50m2 room

Flat rate

Time of Use
43–55c (shoulder)
50–64c (off-peak)
76–98c (peak)

Windows systems, rooms up to 36m2

Split systems, rooms up to 75m2

  • Work best in well-insulated and draught-proofed homes.
  • The outdoor compressor should be in a well ventilated and preferably shaded area.
  • Setting the thermostat to 24–27oC or as high as is comfortable for you, will reduce running costs.
  • Direct louvres at the ceiling, as cold air falls.
  • Systems more than 10 years old typically use more energy and cost more to run.
Ducted evaporative systems

Flat rate

Time of Use
26–35c (shoulder)
31–41c (off-peak)
47–63c (peak)

Whole of house (200m2 home with 125m2  cooled)
  • Effective in South Australia's dry climate. Can also be used as a large fan.
  • Systems need good air flow to operate effectively, opening some windows and doors will help.
  • Additional 6–7c water cost per hour.
Ducted refrigerative systems

Flat rate

Time of Use
$1.34–$1.92 (shoulder)
$1.56–$2.23 (off-peak)
$2.39 - $3.43 (peak)

Whole of house
(200m2 home with 125m2 cooled)
  • Work best in well-insulated and draught-proofed homes, with good quality ductwork.
  • The outdoor compressor should be in a well ventilated and preferably shaded area.
  • Systems with zoning can reduce the size of the area being cooled, using less energy.
  • Setting the thermostat to 24–27oC or as high as is comfortable for you, will reduce running costs.
  • Systems more than 10 years old typically use more energy and cost more to run.

Running costs are a guide only. Calculations are based on AGL’s standing retail contract electricity rates, which are generally aligned with the regulated Default Market Offer. Typical Time of Use shoulder period is 10.00 am-3.00 pm, off-peak is 1.00 am-6.00 am, peak is 6.00 am-10.00 am and 3.00 pm-1.00 am. Flat rate tariffs are charged at the same rate all day.

Methodology is available from the Government of South Australia’s Energy Advisory Service.

You can also get a more accurate idea of how much your cooling costs you to run by:

Buying appliances

Talk to a cooling specialist about the best option for your needs when buying an appliance. The specialist can work out the right cooling power output (rated in kilowatts (kW)) for the size of the area, size and location of windows, and ceiling height.

A cooling appliance that is too small will:

  • not effectively cool your home
  • work constantly for longer periods
  • result in higher than necessary running costs.

Use these cooling outputs as a guide to what could be appropriate for your home. They aren't a substitute for seeking specialist air conditioning advice.

Room size up  to:

  • 20m is 1.5–2.8kW cooling output capacity
  • 30m2 is 2.8– 4.2kW cooling output capacity
  • 40m2 is 4.2 –5.6kW cooling output capacity
  • 50m2 is 5.6–7.0kW cooling output capacity
  • 60m2 is 7.0–8.4kW cooling output capacity.

Take into account the costs associated with installing, running and maintaining the appliance, as well as the purchase price when shopping for a new appliance.

Some appliances can be cheap to buy and run on an hourly basis, but the cooling they provide and the area they can cool could be limited. For example, a portable refrigerated unit might not be enough to cool a large room, but a ducted evaporative system might be able to cool an entire home and cost only a little more per hour to run.

Some refrigerated air conditioners will have an energy rating label that you can use to compare the energy use and efficiency of different appliances. The more stars the better. If two systems have the same kW cooling output capacity but one has more stars than the other, it means it will use less power to achieve the same cooling output and will cost you less to run.

You can compare the estimated running costs of new appliances on the Energy Rating website.

Buying a new cooling appliance can also be a good time to consider your best options for heating. In South Australia, cooling might only be needed at times during a few months each year. Heating can be needed for up to six months. Installing heating and cooling appliances that complement each other, such as reverse cycle air conditioning or an evaporative cooler and a gas space heater, can help to reduce installation and running costs, and greenhouse gas emissions.

Following the manufacturer’s maintenance and cleaning instructions helps your appliance run as efficiently as possible and keeps it safe.

Make sure you're getting the best energy deal

Don’t assume your existing energy provider is offering you the best deal, shop around and switch to save. It’s worth investigating other market offers to see if there is a better energy contract to suit your needs.

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Page last updated 7 December 2022

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