What Size Should My Bathroom Ventilation Fan Be?

Ordinary tasks like showering, bathing and shaving can put home-harming humidity into the air in your Mount Pleasant home. There’s good news though—a modest bathroom ventilation fan can keep you from deformed 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? Olde Towne Heating & Air is here to answer your questions.

Today’s bathroom ventilation fans are small and smooth and they run more quietly and effectively than ever before. You’ll find a large range of selections, from average fans that will get the job done to fans with integrated heat lamps, motion sensors and heat-exchanger ventilation that helps block warmed air from leaking through your ventilation. While you can find a lot of bells and whistles to pick from, the most critical feature 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 move, 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. 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 simple, you can use HGTV’s advice for bathrooms larger than 100 square feet – verify 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 unsure if your bathroom ventilation fan is the right size, or you know it’s the occasion for a new one, give the experts at Olde Towne Heating & Air at call at 843-485-0967. We’re here to help you make sure you have a ventilation fan that will drive hard to guard your home and keep it comfortable. 

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