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With energy prices a constant concern for Australian households, the temperature you set on the air conditioner can make a meaningful difference to your power bill over a summer or winter season. The good news is that a small adjustment to your usual setting, without sacrificing comfort, is one of the easier ways to reduce running costs.
Why the temperature setting matters so much
Air conditioners work harder, and use more electricity, the bigger the gap between the outside temperature and your target indoor temperature. Every extra degree of cooling in summer, or heating in winter, adds to how hard the unit has to work and how much electricity it draws. Over an entire season, a difference of just one or two degrees on the thermostat can add up to a noticeable change in energy use.
A general guide to efficient settings
Energy efficiency guidance in Australia commonly points to a range of around 24 to 26 degrees for cooling in summer, and around 18 to 20 degrees for heating in winter, as a reasonable balance between comfort and running cost. These are general guides rather than fixed rules, and the right setting for your household will depend on the climate you live in, the size and insulation of your home, and personal comfort preferences. If you are currently cooling to 20 or 21 degrees in summer, nudging the setting up a few degrees is often the single easiest change you can make.
Why small changes make a bigger difference than people expect
Many households assume a lower summer setting or higher winter setting will only add a little to the bill, but because the unit has to run longer and harder to reach and maintain a more extreme target temperature, the cost difference is often larger than expected. Setting the thermostat closer to the actual outside conditions, rather than pushing it to an extreme, generally reduces both running time and overall energy draw.
Other habits that support an efficient setting
Use a fan alongside the air conditioner
Ceiling or standing fans help circulate cooled or heated air around the room, which can make a slightly higher (in summer) or lower (in winter) thermostat setting feel just as comfortable, since moving air affects how warm or cool a room feels to the body.
Close doors, curtains and blinds
Reducing direct sunlight through windows in summer, and closing off unused rooms, means the air conditioner is not working to cool or heat more space than necessary.
Set the right mode and fan speed
Many modern air conditioners include an “auto” or “eco” mode that adjusts output based on the room’s current temperature, which can be more efficient than running on a fixed high setting throughout the day.
Maintain the unit
A clean filter and a well-maintained unit generally operate more efficiently than one clogged with dust, since restricted airflow forces the system to work harder to reach the same target temperature.
Avoid constant on-off cycling
Repeatedly switching the unit on and off, rather than maintaining a steady, moderate temperature, can sometimes use more energy overall, since the unit has to work hardest each time it restarts from a warmer or cooler starting point.
Balancing comfort and cost
There is no single perfect number that suits every household, every climate zone and every budget. The most practical approach is to start from a moderate setting, such as the commonly recommended ranges above, and adjust gradually rather than jumping to an extreme. Small, sustained changes to your everyday setting, combined with a few supporting habits like fan use and good insulation, tend to deliver more consistent savings than short bursts of very low or very high settings.
A simple change worth trying
If you are looking for one change to make this season, reviewing your usual thermostat setting and nudging it a degree or two toward a more moderate range is a low-effort place to start. Paired with good habits around fans, insulation and maintenance, it can make a genuine difference to running costs without asking your household to sacrifice comfort.
For more on keeping a home comfortable while managing running costs, see our guide to home orientation, ventilation, shade and running costs.
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