What Size Should My Bathroom Ventilation Fan Be? 07/28/2017Average tasks like showering, bathing and shaving can put home-destructive humidity into the air in your Carlsbad home. There’s good news however—a modest bathroom ventilation fan can keep you from warped wood, mold growth, cracked drywall and other trouble connected 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 noiseless and energy efficient as they could be? Banister's Heating & Air Conditioning Services is here to answer your questions. Today’s bathroom ventilation fans are small and sleek and they work more quietly and economically than ever before. You’ll find a hefty range of options, from average fans that will get the job done to fans with fitted heat lamps, motion sensors and heat-exchanger ventilation that helps avoid warmed air from getting out through your ventilation. While you can find a lot of bells and whistles to choose from, the most critical aspect of your fan is whether or not it’s big 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 normal 8-foot ceiling, your ventilation fan should have a CFM rating about the number of square feet in your bathroom. So, 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 easy, you can heed HGTV’s tips for bathrooms larger than 100 square feet – establish your CFM requirements by toting 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 come to the point for a new one, give the pros at Banister's Heating & Air Conditioning Services at call at 575-887-7777. We’re here to help you guarantee you have a ventilation fan that will drive hard to guard your home and keep it comfortable. You can even schedule an appointment with us online if that’s easiest for you.