Ceiling fans don’t actually cool the air in a room. Instead, they circulate the air, so anyone who is in the room while one is running will feel a sort of breeze. That makes the person feel cooler.
So there’s no point in running a ceiling fan in an empty room.
But for rooms that are usually occupied, a ceiling fan can make the room feel like it’s up to 8 degrees cooler than a room without one. And because the fan circulates cool air, it gives the air conditioning system a break.
In fact, with a ceiling fan running, you can turn your thermostat up by about 4 degrees without sacrificing comfort, according to the U.S. Department of Energy.
A few tips for getting the most energy savings from ceiling fans:
- Rotate the direction that the fan blades spin when the weather warms up. In the summer, ceiling fans should rotate counter-clockwise. That way, the blades push cool air down into the room. In the winter, they should rotate clockwise, to draw warm air up to the ceiling and recirculate it. The rotation isn’t automatic; you have to manually flip a switch on most models.
- Hang the fan seven to nine feet above the floor and about a foot below the ceiling.
- Fan blades should be at least eight inches away from the ceiling and 18 inches from the walls.
- Large ceiling fans move more air than small ones. For a large room, choose a large fan.
- Likewise, large fan blades move the air around more forcefully. So if you’re installing one in a home office or another room where you keep loose papers, choose one with small blades.
- Generally, the more expensive the fan, the quieter it runs.
- Fans with an Energy Star label are about 20 percent more efficient than standard models.