What Temperature Should You Set Your Air Conditioning?
The right setpoint saves energy and keeps you comfortable. Here's what the evidence says for sleeping, working and living.
One of the most common questions we hear after an installation is: 'what temperature should I actually set it to?' The answer depends on what you're trying to achieve — sleeping, working or general comfort — and getting it right can make a meaningful difference to your energy bills.
The recommended range for most rooms
The World Health Organisation (WHO) recommends an indoor temperature of 18–24°C for general comfort. Most people find 22–24°C comfortable during the day, with 18–20°C being optimal for sleeping. These ranges are well-supported by research into thermal comfort and productivity.
Cooling setpoints in summer
During hot weather, the goal is to maintain a comfortable indoor temperature without overcooling. Setting your system to 24–26°C in a living room is typically sufficient to feel noticeably cooler than the outside temperature on a 30°C day. Dropping below 22°C is rarely necessary and significantly increases energy consumption.
Each degree lower you set your air conditioning increases energy consumption by approximately 6–8%. Cooling to 22°C instead of 26°C on a hot day roughly doubles the running cost.
The ideal bedroom temperature for sleep
Sleep research consistently shows that the body sleeps best when the ambient temperature is between 16–19°C. This is cooler than most people set their daytime temperature, and it's why a bedroom air conditioning system on 'sleep mode' is so effective. Sleep mode gradually raises the target temperature through the night as your body temperature naturally drops.
- •Set bedroom AC to 18–20°C for sleep onset
- •Use sleep mode to allow gradual temperature rise through the night
- •Avoid cooling below 16°C — this can cause poor sleep and increased energy use
Home office temperature and productivity
Research from the Helsinki University of Technology found that productivity peaks at around 22°C and begins to decline above 25°C or below 20°C. If you work from home, maintaining a consistent 21–23°C in your office is well supported by the evidence.
Heating setpoints in winter
When using your air conditioning system as a heat pump in winter, the same principles apply in reverse. Most people are comfortable at 19–21°C in a living space and 18°C in a bedroom. There is little benefit to heating above 21°C, and doing so significantly increases energy use. The WHO recommends a minimum of 18°C for adults in good health, and 20°C where vulnerable people or young children are present.
A practical starting point
If you're not sure where to start, set your system to 22°C in your living spaces and 19°C in bedrooms. Adjust from there based on how you feel. Most people find they need very little adjustment once they've dialled in their preferred setpoints.