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 Rapid City home. There’s good news still—a modest bathroom ventilation fan can keep you from deformed wood, mold growth, cracked drywall and other issues 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 quiet and energy efficient as they could be? Street Heating & Sheet Metal 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 hefty range of selections, from average fans that will get the job done to fans with built-in heat lamps, motion sensors and heat-exchanger ventilation that helps prevent warmed air from escaping through your ventilation. While there are a lot of bells and whistles to choose from, the most important feature 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 push, a bathroom ventilation fan should be able to exchange 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 sufficient. If you have a taller ceiling, the equation gets a little more complicated. 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 use HGTV’s advice for bathrooms larger than 100 square feet – verify your CFM requirements by adding 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 pros at Street Heating & Sheet Metal Inc at call at 605-342-5107. We’re here to help you guarantee you have a ventilation fan that will drive hard to care for your home and keep it cozy. You can even schedule an appointment with us online if that’s simplest for you.