What Size Should My Bathroom Ventilation Fan Be? 07/28/2017Average tasks like showering, bathing and shaving can put home-damaging humidity into the air in your Carson City home. There’s good news though—a straightforward bathroom ventilation fan can keep you from deformed wood, mold growth, cracked 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 correct size? Are they as quiet and energy efficient as they could be? Anderson Heating & A/C is here to answer your questions. Today’s bathroom ventilation fans are small and modern and they run more quietly and economically than ever before. You’ll find a great range of choices, from classic 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 escaping through your ventilation. While you can find a lot of bells and whistles to select from, the most critical feature 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 exchange 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 at least 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 sufficient. If you have a larger 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 simple, you can follow HGTV’s tips 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 proper size, or you know it’s time for a new one, give the professionals at Anderson Heating & A/C at call at 775-230-7628. We’re here to help you ensure you have a ventilation fan that will drive hard to protect your home and keep it cozy. You can even arrange an appointment with us online if that’s simplest for you.