professional checking a bathroom ventilation fan

What Size Should My Bathroom Ventilation Fan Be?

Everyday tasks like showering, bathing and shaving can put home-destructive humidity into the air in your McHenry home. There’s good news however—a simple bathroom ventilation fan can save you from warped wood, mold growth, cracked drywall and other issues 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 soft and energy efficient as they could be? Jett's Heating & Air Inc. is here to answer your questions.

Today’s bathroom ventilation fans are small and sleek and they operate more quietly and effectively than ever before. You’ll find a great 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 avoid warmed air from getting out through your ventilation. While you have a lot of bells and whistles to select 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 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 at least 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 satisfactory.

If you have a larger 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 straightforward, you can follow HGTV’s tips 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 unclear if your bathroom ventilation fan is the correct size, or you know it’s time for a new one, give the professionals at Jett's Heating & Air Inc. at call at 815-459-4700. We’re here to help you make sure you have a ventilation fan that will drive hard to protect your home and keep it comfortable. You can even schedule an appointment with us online if that’s easiest for you.