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 Reinholds home. There’s good news however—a modest bathroom ventilation fan can keep you from distorted wood, mold growth, broken drywall and other issues related 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 quiet and energy efficient as they could be? County Line Mechanical LLC is here to answer your questions.

Today’s bathroom ventilation fans are small and smooth and they run more quietly and efficiently than ever before. You’ll find a hefty range of selections, from average 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 getting out through your ventilation. While you can find a lot of bells and whistles to pick from, the most imperative characteristic 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 push, a bathroom ventilation fan should be able to replace 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. 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 straightforward, you can use HGTV’s guidance 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 proper size, or you know it’s come to the point for a new one, give the pros at County Line Mechanical LLC at call at 717-216-0846. We’re here to help you guarantee you have a ventilation fan that will run hard to guard your home and keep it comfy. 

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