Want to save money on your summer air conditioning bills? Then put your ceiling fans to work.
Ceiling fans might be an old technology, but they’re a technology that works. Just as a breeze outdoors can make the day feel colder – a phenomenon known as the wind-chill effect – a breeze indoors can make your house feel cooler than it actually is.
The indoor wind-chill effect from a ceiling fan averages about four degrees. In other words, if the indoor temperature is 80 degrees, turning on a fan will make it feel like it’s 76 degrees, even though a thermometer on the wall wouldn’t register a difference.
Obviously, that four-degree cooling effect is not enough to replace your air conditioner during the hottest parts of our steamy St. Louis area summers. The A/C system will still do the bulk of the cooling work. But fans do allow you to set the thermostat about four degrees higher, without the house feeling any warmer. Setting the thermostat higher means that the air conditioner will not have to do as much work. You’ll save electricity, while reducing the wear and tear on your A/C system and possibly adding a year or more to the air conditioner’s life.
Ceiling fans themselves use a negligible amount of electricity, especially when installed and used correctly. To get the most benefit from your fans, you should:
- Only turn on a fan when you’re in the room, and turn it off when you leave. The wind-chill effect is instantaneous and not cumulative; the room won’t be cooler if you leave the fan on when no one’s home.
- Install fans so that the blades are 10-12 inches from the ceiling and at least 1.5 feet from the walls.
- Use larger fans in larger rooms, or install multiple fans in rooms that are particularly large or long.
- When buying a new ceiling fan, look for one with an Energy Star label.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information about ceiling fans and other HVAC topics, download our free Home Comfort Resource guide.