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 Auburn and Opelika home. There’s good news still—a modest bathroom ventilation fan can keep you from deformed wood, mold growth, damaged 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 proper size? Are they as soft and energy efficient as they could be? Farnell Mechanical, Inc. is here to answer your questions.

Today’s bathroom ventilation fans are small and smooth and they run more quietly and effectively than ever before. You’ll find a large range of options, from simple fans that will get the job done to fans with integrated heat lamps, motion sensors and heat-exchanger ventilation that helps block warmed air from leaking through your ventilation. While you can find a lot of bells and whistles to choose from, the most imperative aspect of your fan is whether or not it’s full-sized 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 normal 8-foot ceiling, your ventilation fan should have a CFM rating about 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 adequate.

If you have a larger ceiling, the equation gets a little more complex. 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 straightforward, you can follow HGTV’s guidance for bathrooms larger than 100 square feet – verify your CFM requirements by toting 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 proper size, or you know it’s time for a new one, give the professionals at Farnell Mechanical, Inc. at call at 334-524-2458. 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 comfortable.