What Size Should My Bathroom Ventilation Fan Be?

Everyday tasks like showering, bathing and shaving can put home-harming humidity into the air in your Alliance home. There’s good news though—a simple bathroom ventilation fan can save you from distorted wood, mold growth, damaged drywall and other problems connected 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? Jack's Refrigeration Heating and Cooling is here to answer your questions.

Today’s bathroom ventilation fans are small and smooth and they work more quietly and effectively than ever before. You’ll find a large range of options, from classic 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 there are a lot of bells and whistles to choose from, the most critical 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 push, 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 at least 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 satisfactory.

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 simple, you can follow HGTV’s advice for bathrooms larger than 100 square feet – establish 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 unsure if your bathroom ventilation fan is the correct size, or you know it’s time for a new one, give the professionals at Jack's Refrigeration Heating and Cooling at call at 308-646-3827. We’re here to help you ensure you have a ventilation fan that will run hard to care for your home and keep it comfortable. 

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