This outdoor five-blade ceiling fan is mounted in a sunroom near a venting skylight. The blades are made of laminated hardwood.
Although people tend to link ceiling fans with summertime, ceiling fans can cut your electric bills in all seasons.
Depending on how you adjust your thermostat settings, they can cut your summertime bills. For cool months in late fall and winter, you can reverse the blade rotations to save energy. You flip the small switch on the side of the ceiling fan housing to reverse the rotation. Run the fan on low speed so it creates a gentle upward breeze (away from people in the room), which will force the warm air — which naturally rises — back down where it's needed. Then, you can set your furnace a few degrees lower and save energy there, too.
If you want to use fans to save energy, it's important to understand how they save energy.
During summer, ceiling fans cool the skin by creating a downward breeze, which should make you feel comfortable enough to turn up the air conditioner a few degrees. Look at the pitch of the blades to determine which rotation direction makes the air blow downward. (Setting the thermostat higher saves much more electricity than the ceiling fan consumes.) In general, during warmer months (late spring and summer), run the ceiling fan on medium or high speed to create the cooling effect. If you install a ceiling fan and don't adjust your thermostat settings accordingly, you may be more comfortable, but it actually increases your cooling electric bills. Also remember that the fan itself does not cool air or things — fans cool people, so they should be turned off when the room is empty.
Some new ceiling fans also have a built-in electric heater with a hand-held remote thermostat/control. It functions the same way as a standard ceiling fan during summer. During winter, it automatically reverses rotation when it is switched to the heating mode. The heater allows you to take advantage of zone heating.
The size of a ceiling fan is rated by the diameter of the blades. This is more important during summer when you want to feel the breeze on your skin. A common sizing rule of thumb is to use a 36-inch fan for rooms up to 150 square feet, a 48-inch fan for up to 300 square feet, and a 52-inch fan for up to 450 square feet. For larger rooms, use two fans spaced about one-quarter of the way in from opposing walls.
Price is often a good indication of the quality of a ceiling fan. Better ceiling fans typically have a greater pitch (twist) on the blades. This requires a more powerful motor, but it moves more air at a lower rotation speed. Lower speed results in less sound and less chance of annoying wobble. Some motors use more copper wire in the windings, up to several miles' worth, so they have a higher price.
A hand-held remote control is a convenient feature included with both inexpensive and pricier models. Natural wood blades are attractive, but inexpensive ones made of synthetic materials are generally well balanced. A rubber-mounted hub reduces noise and vibration. Even the best ceiling fans may require you to attach small balancing weights to stop wobble at high speed.