What Size Should My Bathroom Ventilation Fan Be?

July 28, 2017

Average tasks like showering, bathing and shaving can put home-damaging humidity into the air in your Manassas Park home. There’s good news however—a modest bathroom ventilation fan can save you from distorted wood, mold growth, broken drywall and other issues associated 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 soft and energy efficient as they could be? Woody's Sudden Service Inc is here to answer your questions.

Today’s bathroom ventilation fans are small and modern and they work more quietly and effectively than ever before. You’ll find a hefty range of selections, from classic fans that will get the job done to fans with built-in heat lamps, motion sensors and heat-exchanger ventilation that helps prevent warmed air from escaping through your ventilation. While you can find a lot of bells and whistles to choose from, the most important aspect of your fan is whether or not it’s large 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 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. Thus, if your bathroom is 5 feet by 8 feet, a CFM rating of 40 would be adequate.

If you have a taller ceiling, the equation gets a little more complex. 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 heed HGTV’s advice for bathrooms larger than 100 square feet – verify 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 correct size, or you know it’s come to the point for a new one, give the experts at Woody's Sudden Service Inc at call at 703-278-2036. We’re here to help you guarantee you have a ventilation fan that will work hard to guard your home and keep it comfy.