What is the best air conditioner temperature to save energy and cut costs this summer?

By Phong Ngo June 23, 2025 | 07:19 pm PT

Energy experts advise setting air conditioners to 26 degrees Celsius while at home, raising by 2 degrees during sleep, and by up to 6 degrees when away to reduce electricity use and save money.

A setting of 26 degrees is recommended by the U.S. Environmental Protection Agency’s Energy Star program as the most energy-efficient temperature during the day. However, a 2021 Consumer Reports survey of about 2,280 Americans, cited by USA Today newspaper, found that most preferred setting their air conditioners to 22 degrees.

Air conditioning compressor units. Photo from Unsplash

Choosing a higher temperature can significantly cut energy consumption. "By increasing your AC temperature by 1 degree, you can save about 6% electricity, " India’s Bureau of Energy Efficiency recommends. Setting the temperature at 24 C could lower bills by nearly 24%, it says.

The U.S. Department of Energy recommends raising the thermostat by 2°C at night, when outdoor temperatures usually drop, and by 4–6 C when no one is home. Adjusting the thermostat for at least eight hours a day can cut annual heating and cooling costs by up to 10%.

To minimize unnecessary energy use, American energy provider Reliant suggests the "4-by-4" rule: increase your thermostat by 4 C when away for more than four hours.

For added convenience, the U.S.-based National Heating and Air Conditioning Company suggests using a programmable thermostat, which can automatically adjust temperatures based on daily routines.

Many models feature touchscreen controls, Wi-Fi connectivity, and allow for remote access via smartphone or computer.