Before air conditioning, ceiling fans were a popular way to produce a cooling breeze in a hot room.
Whether they make sense today depends. They can be energy wasters or energy savers.
With air conditioning
If you live in a hot climate and have air conditioning you might be tempted to install ceiling fans to try reducing your energy bills. In the spring and fall, or in the morning or evening, you could turn the AC off and use ceiling fans.
This strategy might be quite comfortable, and you might save on your bills if you are very disciplined. But most people have found it ends up costing more to put in the fans than it’s worth.
Along the coast in California houses are usually built without air conditioning. It’s just not hot enough to justify the cost.
Ceiling fans can be a great idea in this climate. The moving air cools you off, and these fans cover a much wider area than a portable fan would.
When to use fans
Here’s the key to making energy efficient use of fans—they don’t cool anything in an empty room. So it’s good to develop the habit of turning them off when leaving the room, just like turning off a light. In fact the motor in the fan gives off a bit of heat, so running them when you’re out actually heats up the house.
To make it easy to turn off fans, be sure to have your contractor install wall switches. People are a lot more likely to use a simple switch than a pull chain.
In the winter some folks use fans to bring heated air back down from the ceiling to people height. Opinion is mixed on whether this actually works, or saves energy. So try it for yourself and see what you think.