What Size Should My Bathroom Ventilation Fan Be?

July 28, 2017

Average tasks like showering, bathing and shaving can put home-harming humidity into the air in your Hodgenville home. There’s good news still—a modest bathroom ventilation fan can save you from distorted wood, mold growth, cracked drywall and other problems related 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 noiseless and energy efficient as they could be? Phelps Heating & Cooling is here to answer your questions.

Today’s bathroom ventilation fans are small and sleek and they operate more quietly and efficiently than ever before. You’ll find a great range of choices, from simple 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 big enough to do its job.

Assessed by the cubic feet per minute (CFM) of air they transfer, a bathroom ventilation fan should be able to exchange the air in a bathroom at least eight times an hour. With a typical 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 adequate.

If you have a larger 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 heed 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 unsure if your bathroom ventilation fan is the correct size, or you know it’s come to the point for a new one, give the pros at Phelps Heating & Cooling at call at 270-358-3167. We’re here to help you make sure you have a ventilation fan that will run hard to care for your home and keep it comfy.