What Size Should My Bathroom Ventilation Fan Be?

Average tasks like showering, bathing and shaving can put home-destructive humidity into the air in your Mechanicsville home. There’s good news however—a modest bathroom ventilation fan can protect you from distorted wood, mold growth, broken drywall and other issues connected 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 noiseless and energy efficient as they could be? M & S Heating & Air LLC is here to answer your questions.

Today’s bathroom ventilation fans are small and smooth and they work more quietly and economically 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 avoid warmed air from leaking through your ventilation. While there are a lot of bells and whistles to choose from, the most imperative characteristic of your fan is whether or not it’s big enough to do its job.

Graded by the cubic feet per minute (CFM) of air they transfer, a bathroom ventilation fan should be able to replace 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. Therefore, if your bathroom is 5 feet by 8 feet, a CFM rating of 40 would be satisfactory.

If you have a taller 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 guidance 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 unclear if your bathroom ventilation fan is the right size, or you know it’s come to the point for a new one, give the pros at M & S Heating & Air LLC at call at 301-363-4699. We’re here to help you guarantee you have a ventilation fan that will drive hard to protect your home and keep it comfortable. 

Back To Blog