What Size Should My Bathroom Ventilation Fan Be? 07/28/2017Everyday tasks like showering, bathing and shaving can put home-destructive humidity into the air in your Topeka home. There’s good news however—a straightforward bathroom ventilation fan can save you from deformed 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? Custom Sheetmetal & Roofing, Inc. is here to answer your questions. Today’s bathroom ventilation fans are small and sleek and they operate more quietly and efficiently than ever before. You’ll find a great range of options, from classic fans that will get the job done to fans with fitted heat lamps, motion sensors and heat-exchanger ventilation that helps block warmed air from getting out through your ventilation. While you have a lot of bells and whistles to choose from, the most important characteristic of your fan is whether or not it’s full-sized enough to do its job. Assessed by the cubic feet per minute (CFM) of air they move, a bathroom ventilation fan should be able to swap out the air in a bathroom at least eight times an hour. With a standard 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 adequate. 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 simple, you can heed HGTV’s advice 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 proper size, or you know it’s the occasion for a new one, give the professionals at Custom Sheetmetal & Roofing, Inc. at call at 785-357-6200. We’re here to help you ensure you have a ventilation fan that will drive hard to care for your home and keep it cozy. You can even set up an appointment with us online if that’s easiest for you.