Which direction should a ceiling fan turn for cooling, and does a fan lower the temperature?

Summer direction: counterclockwise

The U.S. Department of Energy (DOE) gives a plain rule in its 2022 Energy Saver Guide. It says, "In summer, use the ceiling fan in a counterclockwise direction to create a wind chill effect."

The ENERGY STAR name is a trademark of the U.S. Environmental Protection Agency (EPA), and Natural Resources Canada runs it in Canada. The Canadian page says to operate your ceiling fan counterclockwise in the summer and clockwise in the winter. It also lists the ability to reverse the motor and airflow direction as a key feature of certified fans.

One fan maker's owner's manual describes what summer mode does. In the warm weather setting, it says, the fan turns counterclockwise and a downward air flow creates a cooling effect.

How to change the direction

The fan maker's owner's manual says a slide switch controls direction, forward or reverse. Its forward setting is the warm weather position, where the fan turns counterclockwise. Its reverse setting is the cool weather position, where the fan turns clockwise. The manual adds that the right speed depends on things like room size, ceiling height and the number of fans.

The same manual gives one safety step. It says, "Turn off and wait for fan to stop before changing the setting of the forward/reverse slide switch."

Installing, rewiring or remounting a ceiling fan is electrical work, so call a licensed electrician for that.

Does a ceiling fan lower the temperature?

No. Tampa Electric, an electric utility, puts it simply. "Fans don't lower room temps, but they do make you feel cooler."

The ENERGY STAR page in Canada says the same thing another way. Fans don't actually cool a room. They cool the occupants by circulating air.

A fan also adds heat. The FSEC paper says ceiling fans give off heat and use electricity. A second FSEC report says all of the energy a fan uses is eventually converted to heat within the home. That heat must eventually be removed by ventilation air or the cooling system.

For other ways to stay comfortable, see our guide on how to keep a house cool without AC.

Raise the thermostat, or the fan does not help

The DOE's 2022 guide says ceiling fans can allow you to turn up the thermostat a few degrees. It gives a number, saying a ceiling fan allows you to turn up the thermostat about 4°F without any loss in comfort.

Tampa Electric gives the same 4 degree figure. It says you can raise your thermostat by 4 degrees and still feel comfortable.

The FSEC paper notes that comfort studies show people prefer higher temperatures when a breeze is on them. The catch is that you have to actually raise the thermostat. The FSEC paper says ceiling fans save energy if their use also results in reduced air conditioner use. It also found that if fans are used with little or no thermostat change, energy use can actually be increased.

In short, set the thermostat higher while the fan runs on you. For more on picking a set point, see our guide to thermostat settings. If the house stays too warm even then, read why an AC can't keep up with the heat.

What Florida research found

A 1996 FSEC paper analyzed a survey and a smaller monitoring study of Florida homes, which it cites to a 1995 Florida Power and Light report. The paper reports metered results from 400 Florida households that indicate no cooling energy savings due to ceiling fans.

Homeowner-reported thermostat settings were the same for homes with and without ceiling fans.

A later FSEC report cites survey data from 386 Central Florida households and reaches the same finding. It says the data suggests no statistically valid difference in thermostat settings between homes using fans and those without them.

The researchers offered possible reasons. Fans may improve comfort without cooling enough to make people raise the set point. Fans are left on when no one is in a room. Some people may also wrongly believe that ceiling fans cool the air.

These studies are decades old, but the lesson still matches current DOE advice: raise the thermostat and switch fans off in empty rooms.

Winter direction, and why the benefit is doubtful

The DOE's 2022 guide says, "In winter, reverse the fan to run clockwise and force warm air down from the ceiling." The fan maker's manual says that in the clockwise setting an upward airflow moves warm air off the ceiling area.

An FSEC report cites a Consumer Reports chamber study. That study showed that the long-reported de-stratification benefits when heating are largely unsubstantiated.

If you do switch to clockwise for a cool spell, remember to switch back before the heat returns. Left on clockwise, the fan pushes air up toward the ceiling instead of down onto you.