Can You Leave Ceiling Fans Running?

Can You Leave Ceiling Fans Running?

There are many ceiling fan designs to choose from, with variations in the style and color of the material that houses the fan’s engine, the blade material--including color and length--and the inclusion or absence of lights as part of the unit. In addition to complementing your décor, ceiling fans are practical tools to help reduce your energy costs. Knowing when to leave a ceiling fan running, and when to turn it off, can make a difference in your utility bills.

How They Work

According to Energy Star, ceiling fans create a cooling effect by stirring the air. In the summer, the blades should turn counterclockwise, forcing air down into the room to create a breeze. If your ceiling fan allows you to change the rotation direction of the blades, set them to turn clockwise to produce an updraft in the winter. This blows air up to the ceiling and displaces the warm air that has risen, forcing it back down into the room.


If you plan to leave your ceiling fan running for longer periods of time, the website House Energy recommends purchasing a fan with a direct-drive motor instead of a friction-drive motor. Direct-drive motors operate more quietly, with greater efficiency, and last longer.

Ceiling fans come in high, medium and low grades. The higher the grade, the more expensive the fan. For continuous use, choose a high-grade fan that has a larger motor. If you plan to use your fan less than 12 hours per day, choose a medium-grade fan. For infrequent use, select a low-grade model.

When to Turn Off

The University of Florida Extension states that ceiling fans do not change the temperature in a room. Instead, the breeze created by a ceiling fan cools your skin, causing you to feel more comfortable and allowing you to raise your thermostat setting up to four degrees. You can leave a ceiling fan running. But because ceiling fans do not lower a room’s temperature, you should turn them off to reduce electricity costs when no one is in the room.


To maximize their efficiency, the American Lighting Association advises choosing the right-sized ceiling fan for your room. To determine size, measure the ceiling fan’s diameter from blade tip to blade tip. For rooms of 75 square feet or less, select a 29-inch to 36-inch fan. Rooms that measure up to 144 square feet need fans no larger 36 to 42 inches. For larger rooms, select ceiling fans of up to 54 inches. Alternately, position several smaller ceiling fans in different locations in larger rooms, such as over a conversation setting and television area.


Ceiling fans can help reduce your electricity bills, but they also consume energy. The website Home Energy recommends buying models with the greatest air flow efficiency, measured in cubic feet per minute per watt or CFM/watt, at each of the fan’s operating speeds. You should also choose Energy Star-rated light kits and use energy-efficient bulbs in your ceiling fan when possible.