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 Florissant home. There’s good news though—a straightforward bathroom ventilation fan can save you from distorted wood, mold growth, broken drywall and other problems associated 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? B & B Heating & Cooling is here to answer your questions. Today’s bathroom ventilation fans are small and sleek and they operate more quietly and economically than ever before. You’ll find a hefty range of choices, from classic fans that will get the job done to fans with built-in heat lamps, motion sensors and heat-exchanger ventilation that helps block warmed air from getting out through your ventilation. While there are 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 push, 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 almost 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 satisfactory. 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 straightforward, you can use HGTV’s advice 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 unsure if your bathroom ventilation fan is the correct size, or you know it’s time for a new one, give the professionals at B & B Heating & Cooling at call at 314-838-9800. We’re here to help you ensure you have a ventilation fan that will work hard to protect your home and keep it cozy. You can even schedule an appointment with us online if that’s the most straightforward for you.