What Temperature to Set Your Air Conditioner in Winter in Australia: A Practical Guide
Wondering what temperature to set your air conditioner in winter in Australia? For most homes, setting a reverse-cycle air conditioner to 18–20°C in HEAT mode is a practical starting point. The most comfortable setting will still depend on the local climate, room size, insulation and how the space is used. This guide explains how to choose and maintain an efficient winter setting.
What Temperature Should You Set Your Air Conditioner to in Winter?
For most Australian homes, 18–20°C in HEAT mode is a practical starting point during winter. In colder parts of the country, some households may find 20–21°C more comfortable, while homes in milder climates may be comfortable at 18–19°C. Rather than using one fixed temperature for each state or territory, it is better to treat these settings as a general guide and adjust them based on insulation, room size and household comfort.
Winter Air Conditioner Temperature Guide by State and Territory
State or Territory | Typical Winter Conditions | Suggested Starting Setting |
New South Wales | Mild on the coast; colder inland and at higher elevations | 18–20°C |
Victoria | Cool winters with cold mornings and nights | 18–20°C; up to 21°C if needed |
Queensland | Mild in the south-east; warmer in the north | 18–20°C where heating is needed |
Tasmania | Generally colder, with frequent cold mornings | 18–20°C; up to 21°C if needed |
South Australia | Cool in the south, with colder inland nights | 18–20°C |
Western Australia | Mild in Perth and the south-west; warm in the north | 18–20°C where heating is needed |
Northern Territory | Warm in the Top End; cold nights possible inland | Usually unnecessary in the Top End; 18–20°C inland |
Australian Capital Territory | Cold winters with frosty mornings and nights | 18–20°C; up to 21°C if needed |
Source: Simplyair
These ranges are best used as a starting point rather than a fixed rule. A well-insulated home may feel comfortable at 18°C, while a larger or draughtier room may need 20°C or slightly above. If the room still feels cold, increase the setting by 1°C at a time instead of jumping straight to a much higher temperature.
Why Does the Right Air Conditioner Temperature Matter in Winter?
The temperature setting affects more than how warm the room feels. It can also influence energy use, household costs, sleep and comfort during everyday activities.
Comfort: A moderate setting keeps the room comfortably warm without making it feel stuffy or overheated. The ideal temperature may vary with insulation, room size and personal preference.
Energy Efficiency: Higher settings increase the amount of heating required, which may cause the air conditioner to run longer. A steady, moderate temperature helps avoid unnecessary energy use.
Heating Costs: Each additional degree can increase heating costs by around 5%–10%. The final amount also varies with the unit’s capacity, efficiency and daily runtime, so checking how much electricity your air conditioner uses can provide a more realistic estimate of winter running costs.
Sleep Quality: An overheated bedroom can make it harder to settle and stay comfortable overnight. A slightly cooler, stable setting is generally more suitable for sleep than maintaining high heat throughout the night.
Focus and Productivity: Spaces that are too warm may feel stuffy and contribute to tiredness, while cold rooms can be distracting. A comfortable temperature can support concentration when working or studying at home.
What Determines the Right Air Conditioner Temperature in Winter?
The same thermostat setting can feel quite different from one home to another. The amount of heating required depends on the local climate, how quickly the building loses warmth, the characteristics of the room and whether the air conditioner is suited to the space.
Local Climate and Exposure
Australia covers several climate zones, so winter heating needs vary considerably between regions. Altitude, coastal or inland location, wind exposure and overnight temperatures can all influence how much heating a home requires. Australia’s Zoned Energy Rating Label therefore assesses air conditioners across hot, average and cold climate zones rather than using one national performance rating.
Insulation, Windows and Draughts
How well the room retains warmth can affect whether 18°C feels comfortable or still feels cool. Ceiling and wall insulation, well-sealed doors and windows, and higher-performing glazing can help reduce heat loss.
By contrast, gaps around doors, windows and other openings can allow warm air to escape and cold draughts to enter. Single-glazed windows also provide less insulation than double glazing. Sealing obvious gaps and closing curtains after sunset may improve comfort without requiring a higher thermostat setting.
Room Size and Layout
Floor area alone does not determine heating demand. High ceilings, open-plan layouts, stairwells and adjoining rooms increase the volume of space being heated and can make it harder to maintain an even temperature. A smaller enclosed bedroom may therefore feel warm at a setting that is less effective in a large living area.
Sunlight and Orientation
Natural solar gain can change how much mechanical heating a room needs during the day. In many Australian climates, north-facing living areas and windows can receive low-angle winter sunlight, while shaded rooms or spaces with limited solar access may remain cooler. The effect varies in tropical northern Australia, where reducing heat gain is often more important than maximising winter sun.
Air Conditioner Capacity and Climate Suitability
The air conditioner needs enough heating capacity for the room’s size, layout and local climate. When choosing the right air conditioner size, consider the floor area, ceiling height, insulation, window exposure and whether the space is open plan. A system that is too small may run for longer without bringing the room up to the selected temperature on colder days.
How the Room Is Used
The most suitable temperature also depends on the room’s purpose and occupants. A living area used throughout the evening may need steadier warmth than a bedroom, while activity level, clothing and individual sensitivity to cold can change what feels comfortable.
How to Set and Use Your Air Conditioner Efficiently in Winter
Once you have selected a suitable temperature, a few adjustments can help the air conditioner maintain warmth without unnecessary energy use.
1. Use HEAT Mode and Adjust Gradually
Select HEAT mode, usually shown by a sun symbol, and give the room time to warm up. If it still feels cool, increase the setting by 1°C at a time rather than immediately choosing a much higher temperature. If you are unsure what the temperature of the room is, use an indoor thermometer rather than relying only on the number shown on the air conditioner.
2. Focus Heating Where It Is Needed
Heating only the occupied space can be more practical than warming unused areas. Close doors to empty rooms and use zoning controls where available.
For more flexible room-by-room heating, the EcoFlow WAVE 3 Portable Air Conditioner can be moved between indoor spaces and provides both heating and cooling. Its app allows households to change modes, check battery status and schedule shutdowns from a phone.
3. Improve Airflow and Retain Warmth
Angle the louvres downwards, so warm air reaches the occupied area before rising. Open curtains when winter sunlight is available, close them before dark and reduce draughts around windows and doors. Filters and vents should also be cleaned regularly to maintain airflow and heating performance.
4. Monitor and Manage Connected Power
A portable power station can provide flexible power for WAVE 3 and other compatible appliances while giving households greater visibility over connected energy use.
The EcoFlow DELTA 3 Max Plus Portable Power Station includes an energy dashboard for tracking usage and battery status, along with Smart Output Priority for managing selected connected loads. Its multiple charging options also make it easier to replenish stored power around household routines.
Energy monitoring and output controls apply to compatible connected appliances. A hardwired split or ducted air conditioner would require suitable home integration and, where electrical work is involved, a licensed electrician.
Conclusion
When deciding what temperature to set your air conditioner in winter in Australia, 18–20°C in HEAT mode is a sensible starting point for most homes. Adjust it gradually, direct warm air into occupied spaces and reduce draughts to maintain comfort without unnecessary energy use.
EcoFlow WAVE 3 suits targeted room heating, while DELTA 3 Max Plus can power compatible appliances and provide clearer visibility over connected energy use.
FAQs
Is 22 degrees hot for aircon?
A setting of 22°C in HEAT mode is fairly warm for an Australian winter, but it is not unusually high. Most homes can start at 18–20°C and move up gradually if the room still feels chilly. Keeping the setting lower where comfortable can also help avoid adding unnecessarily to the power bill.
How to use split AC in winter?
Switch the split system to HEAT mode, usually marked by a sun symbol, and set it to around 18–20°C. Point the louvres down so warm air reaches the living area, keep doors and windows closed, and give the unit a few minutes to start heating. Clean filters regularly to maintain steady airflow.
Is it safe to run AC at 30 degrees in winter?
Although many split systems allow a 30°C heating setting, it is much warmer than most Australian homes need. The unit may run for longer trying to reach that temperature, increasing energy use and making the room feel overheated. Start closer to 18–20°C and raise it one degree at a time when needed.