What Size Should My Bathroom Ventilation Fan Be?

July 28, 2017

Everyday tasks like showering, bathing and shaving can put home-harming humidity into the air in your Northglenn home. There’s good news however—a modest bathroom ventilation fan can save you from distorted wood, mold growth, cracked drywall and other trouble related 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 noiseless and energy efficient as they could be? Northglenn Heating & Air Conditioning, Inc. is here to answer your questions.

Today’s bathroom ventilation fans are small and modern and they work 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 fitted heat lamps, motion sensors and heat-exchanger ventilation that helps prevent warmed air from leaking 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 transfer, a bathroom ventilation fan should be able to swap out the air in a bathroom at least eight times an hour. With a typical 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 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 follow HGTV’s tips for bathrooms larger than 100 square feet – establish 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 right size, or you know it’s time for a new one, give the professionals at Northglenn Heating & Air Conditioning, Inc. at call at 303-452-4146. We’re here to help you ensure you have a ventilation fan that will run hard to protect your home and keep it comfy.