Choosing a Bathroom Fan

Bathroom exhaust/ventilation fans are key to preventing humidity and moisture buildup, which can damage paint, lead to the growth of mold and mildew, and harm drywall and wood supports. Use these tips to choose a fan that is sized and vented appropriately for your bathroom.


Where your bathroom is located will usually determine what kind of fan you should buy. A ceiling-mounted fan vents into the attic or out through the roof. When there is no practical way to vent through the roof, a wall-mounted fan that is installed on an external wall would be more appropriate. If you install a wall-mounted fan, you may want to consider a model with a heat exchanger, which uses warm outgoing air to heat cooler incoming air. Although these are more expensive, they can help keep your heating bills in check.


According to recommendations from the Home Ventilating Institute, a bathroom ventilation system should change the air eight times an hour, or one cubic foot per minute (CFM) per square foot of bathroom, with a minimum of 50 CFM. For example, a bathroom measuring 8 feet by 10 feet would indicate a fan rated for at least 80 CFM. If your bathroom measures larger than 100 square feet, you should also add 50 CFM for each toilet, shower, and bathtub (100 CFM for a whirlpool tub).


Typically, the exhaust points for bathroom ventilations fans should be installed near the shower or tub and in an enclosed water closet.

Energy Efficiency

Energy Star-rated bathroom fans use 20% less energy than minimum federal guidelines. Many fans come with electricity-saving options, such as an on/off timer, humidity sensors, or motion sensors.


Most people want to buy the quietest fan they can afford. The number of "sones" on a fan rating will help you determine how loud it will be. The higher the number of sones, the noisier the fan. For reference, a rating of 0.5 to 1.2 sones means the fan is exceptionally quiet. A rating of 1.5 to 2.0 sones is very good. Fans rated higher than 4.0 sones tend to be noisy.


Once you've determined the type of fan that is right for your bathroom, you can look for additional features to increase your comfort level. Bathroom fans can come with lights, heaters, and even nightlights. And they don't have to look boring, either. Just as your other bathroom accessories do, bathroom fans come in a wide variety of styles. Whether your taste is contemporary, traditional, or industrial, be sure to select the fan that looks best in your bathroom.