What Size Should My Bathroom Ventilation Fan Be?

Everyday tasks like showering, bathing and shaving can put home-damaging humidity into the air in your Jefferson City home. There’s good news though—a straightforward bathroom ventilation fan can save you from warped 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 correct size? Are they as soft and energy efficient as they could be? Stieferman Heating Company Inc is here to answer your questions.

Today’s bathroom ventilation fans are small and sleek and they operate more quietly and efficiently than ever before. You’ll find a large range of choices, 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 you have a lot of bells and whistles to choose from, the most imperative aspect of your fan is whether or not it’s full-sized 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 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 almost as high as the number of square feet in your bathroom. So, 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 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 straightforward, you can use HGTV’s guidance 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 unsure if your bathroom ventilation fan is the correct size, or you know it’s the occasion for a new one, give the pros at Stieferman Heating Company Inc at call at 573-203-3908. We’re here to help you ensure you have a ventilation fan that will work hard to protect your home and keep it comfortable. 

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