What Size Should My Bathroom Ventilation Fan Be?

Ordinary tasks like showering, bathing and shaving can put home-destructive humidity into the air in your Pacheco home. There’s good news though—a straightforward bathroom ventilation fan can keep you from distorted wood, mold growth, broken drywall and other trouble connected 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 soft and energy efficient as they could be? Clean Air HVAC 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 hefty 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 block warmed air from leaking through your ventilation. While there are a lot of bells and whistles to select from, the most critical characteristic of your fan is whether or not it’s full-sized 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 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 almost 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 sufficient.

If you have a higher 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 use HGTV’s tips for bathrooms larger than 100 square feet – establish 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 unclear if your bathroom ventilation fan is the proper size, or you know it’s the occasion for a new one, give the pros at Clean Air HVAC at call at 925-233-6238. We’re here to help you guarantee you have a ventilation fan that will run hard to protect your home and keep it comfortable. 

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