professional checking a bathroom ventilation fan

What Size Should My Bathroom Ventilation Fan Be?

Everyday tasks like showering, bathing and shaving can put home-damaging humidity into the air in your Saint Louis home. There’s good news though—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 correct size? Are they as soft and energy efficient as they could be? Morgner Incorporated Air Conditioning & Heating is here to answer your questions.

Today’s bathroom ventilation fans are small and sleek and they operate more quietly and economically than ever before. You’ll find a hefty range of options, from classic 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 leaking through your ventilation. While you have a lot of bells and whistles to choose from, the most important characteristic 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 move, a bathroom ventilation fan should be able to replace 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. Therefore, 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 straightforward, you can follow HGTV’s tips 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 unsure if your bathroom ventilation fan is the proper size, or you know it’s come to the point for a new one, give the pros at Morgner Incorporated Air Conditioning & Heating at call at 314-961-0875. We’re here to help you ensure you have a ventilation fan that will drive hard to care for your home and keep it cozy. You can even arrange an appointment with us online if that’s easiest for you.