What Size Should My Bathroom Ventilation Fan Be?

Air Quality

Ordinary tasks like showering, bathing and shaving can put home-damaging humidity into the air in your Lexington home. There’s good news though—a modest bathroom ventilation fan can save you from distorted wood, mold growth, damaged drywall and other problems connected with a humid bathroom.

Even if you have ventilation fans in your bathrooms, do you know if they’re the right size? Are they as noiseless and energy efficient as they could be? Kelley Mechanical is here to answer your questions.

Today’s bathroom ventilation fans are small and modern and they operate 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 avoid warmed air from getting out through your ventilation. While you have a lot of bells and whistles to select from, the most critical characteristic of your fan is whether or not it’s full-sized enough to do its job.

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

If you have a higher ceiling, the equation gets a little more complicated. 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 guidance for bathrooms larger than 100 square feet – establish your CFM requirements by increasing 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 time for a new one, give the professionals at Kelley Mechanical at call at 859-209-3003. We’re here to help you make sure you have a ventilation fan that will run hard to care for your home and keep it comfortable. You can even schedule an appointment with us online if that’s the most straightforward for you.

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