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 Rocky Mount home. There’s good news though—a straightforward bathroom ventilation fan can save you from warped wood, mold growth, damaged drywall and other trouble 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 quiet and energy efficient as they could be? Davis Heating & Air Conditioning is here to answer your questions.

Today’s bathroom ventilation fans are small and smooth and they operate more quietly and economically than ever before. You’ll find a great range of choices, from average fans that will get the job done to fans with integrated 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 pick from, the most imperative aspect 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 at least 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 satisfactory.

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 simple, you can use HGTV’s tips for bathrooms larger than 100 square feet – establish 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 not sure if your bathroom ventilation fan is the right size, or you know it’s time for a new one, give the pros at Davis Heating & Air Conditioning at call at 540-483-5605. We’re here to help you make sure you have a ventilation fan that will work hard to care for your home and keep it comfortable. You can even arrange an appointment with us online if that’s easiest for you.