What Size Should My Bathroom Ventilation Fan Be?

Ordinary tasks like showering, bathing and shaving can put home-damaging humidity into the air in your Lake Forest home. There’s good news still—a simple bathroom ventilation fan can protect you from deformed wood, mold growth, broken drywall and other issues connected 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 soft and energy efficient as they could be? 1st Choice Heating & Air Conditioning, Inc. is here to answer your questions.

Today’s bathroom ventilation fans are small and sleek and they work more quietly and effectively 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 avoid warmed air from escaping through your ventilation. While there are a lot of bells and whistles to choose from, the most important aspect of your fan is whether or not it’s large enough to do its job.

Rated 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 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 sufficient.

If you have a taller 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 easy, you can heed HGTV’s advice for bathrooms larger than 100 square feet – verify 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 unclear if your bathroom ventilation fan is the correct size, or you know it’s time for a new one, give the pros at 1st Choice Heating & Air Conditioning, Inc. at call at 949-204-0859. 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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