What Size Should My Bathroom Ventilation Fan Be?

July 28, 2017

Everyday tasks like showering, bathing and shaving can put home-damaging humidity into the air in your Naples home. There’s good news though—a straightforward bathroom ventilation fan can save you from warped wood, mold growth, cracked drywall and other problems associated 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 soft and energy efficient as they could be? Speedy Air Conditioning is here to answer your questions.

Today’s bathroom ventilation fans are small and sleek and they work more quietly and economically than ever before. You’ll find a large range of selections, from simple fans that will get the job done to fans with fitted heat lamps, motion sensors and heat-exchanger ventilation that helps prevent warmed air from getting out through your ventilation. While you can find a lot of bells and whistles to choose from, the most important feature 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 move, 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 about 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 taller 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 simple, you can use HGTV’s guidance for bathrooms larger than 100 square feet – determine 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 unclear if your bathroom ventilation fan is the correct size, or you know it’s the occasion for a new one, give the professionals at Speedy Air Conditioning at call at 239-244-3439. We’re here to help you ensure you have a ventilation fan that will run hard to guard your home and keep it cozy.