Ceiling fans effectively circulate the air in a room to create a draft throughout the room. If you use air conditioning, a ceiling fan will allow you to raise the thermostat setting about 4°F with no reduction in comfort. In temperate climates, or during moderately hot weather, ceiling fans may allow you to avoid using your air conditioner altogether. Install a fan in each room that needs to be cooled during hot weather. Turn off ceiling fans when you leave a room; fans cool people, not rooms, by creating a wind chill effect.
Let’s do the math. An air conditioner costs $0.36 per hour, and a ceiling fan only $0.01 per hour. If air conditioning costs are lowered even by a few cents per hour, fans could still be worth it. On average, ceiling fans can help save four to eight percent on cooling costs when combined with an air conditioner.
If you live in a climate where you can use fans instead of air conditioning on marginally hot days, then ceiling fans could be a very worthwhile investment.
While ceiling fans providebetter circulation of cool air and a wind-chill effect, they can still amount to wasted money and energy if no one is enjoying these benefits. For example, don’t:
Install fans in rooms that aren’t used very often;
Keep fans running after everyone leaves a room; and
Turn on fans whenever the lights are on, even if the fan is not needed.