What Size Should My Bathroom Ventilation Fan Be?

Average tasks like showering, bathing and shaving can put home-destructive humidity into the air in your Greensburg home. There’s good news though—a straightforward bathroom ventilation fan can protect 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 correct size? Are they as soft and energy efficient as they could be? Wallpe Heating & Cooling is here to answer your questions.

Today’s bathroom ventilation fans are small and sleek and they run more quietly and economically than ever before. You’ll find a great range of choices, from classic 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 escaping through your ventilation. While there are a lot of bells and whistles to select from, the most imperative feature of your fan is whether or not it’s big enough to do its job.

Assessed 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 standard 8-foot ceiling, your ventilation fan should have a CFM rating about 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 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 straightforward, you can heed HGTV’s guidance for bathrooms larger than 100 square feet – determine 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 not sure if your bathroom ventilation fan is the right size, or you know it’s time for a new one, give the pros at Wallpe Heating & Cooling at call at 812-638-4232. We’re here to help you make sure you have a ventilation fan that will drive hard to guard your home and keep it comfy. 

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