What Size Should My Bathroom Ventilation Fan Be?

July 28, 2017

Average tasks like showering, bathing and shaving can put home-destructive humidity into the air in your Bartlesville home. There’s good news though—a simple bathroom ventilation fan can protect you from warped wood, mold growth, broken drywall and other problems related with a humid bathroom.

Even if you have ventilation fans in your bathrooms, do you know if they’re the proper size? Are they as quiet and energy efficient as they could be? Farris Heating & Air is here to answer your questions.

Today’s bathroom ventilation fans are small and smooth and they work more quietly and effectively than ever before. You’ll find a hefty range of selections, from simple fans that will get the job done to fans with integrated heat lamps, motion sensors and heat-exchanger ventilation that helps prevent warmed air from escaping through your ventilation. While there are a lot of bells and whistles to select from, the most critical characteristic of your fan is whether or not it’s large enough to do its job.

Graded by the cubic feet per minute (CFM) of air they push, a bathroom ventilation fan should be able to exchange the air in a bathroom at least eight times an hour. With a standard 8-foot ceiling, your ventilation fan should have a CFM rating almost as high as the number of square feet in your bathroom. Therefore, if your bathroom is 5 feet by 8 feet, a CFM rating of 40 would be satisfactory.

If you have a higher ceiling, the equation gets a little more difficult. You’ll want to multiply the width of the room by its height and length, divide it by 60 and multiply by 8. Or, to keep it easy, you can use HGTV’s advice for bathrooms larger than 100 square feet – establish your CFM requirements by adding 50 CFM for every toilet; 50 CFM for each shower, bath and combo; and 100 CFM for each whirlpool.

If you’re not sure if your bathroom ventilation fan is the right size, or you know it’s the occasion for a new one, give the experts at Farris Heating & Air at call at 918-534-8194. We’re here to help you make sure you have a ventilation fan that will drive hard to care for your home and keep it comfy.