What Size Should My Bathroom Ventilation Fan Be?

Average tasks like showering, bathing and shaving can put home-harming humidity into the air in your Robstown home. There’s good news though—a straightforward bathroom ventilation fan can keep you from warped wood, mold growth, damaged 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 noiseless and energy efficient as they could be? McNatt Inc is here to answer your questions.

Today’s bathroom ventilation fans are small and smooth and they run more quietly and economically than ever before. You’ll find a great range of options, from simple fans that will get the job done to fans with built-in heat lamps, motion sensors and heat-exchanger ventilation that helps block warmed air from getting out through your ventilation. While you can find a lot of bells and whistles to choose from, the most imperative aspect of your fan is whether or not it’s large 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 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 easy, you can follow HGTV’s tips 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 not sure if your bathroom ventilation fan is the correct size, or you know it’s the occasion for a new one, give the experts at McNatt Inc at call at 361-247-0605. We’re here to help you ensure you have a ventilation fan that will drive hard to care for your home and keep it comfortable. 

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