What Size Should My Bathroom Ventilation Fan Be? 07/28/2017Ordinary tasks like showering, bathing and shaving can put home-damaging humidity into the air in your Olathe home. There’s good news though—a modest bathroom ventilation fan can save you from distorted 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 soft and energy efficient as they could be? Polestar Plumbing, Heating & Air Conditioning 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 average fans that will get the job done to fans with built-in heat lamps, motion sensors and heat-exchanger ventilation that helps avoid warmed air from leaking through your ventilation. While there are a lot of bells and whistles to pick from, the most imperative characteristic of your fan is whether or not it’s big enough to do its job. Graded 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 typical 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 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 straightforward, you can heed HGTV’s guidance for bathrooms larger than 100 square feet – verify 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 not sure if your bathroom ventilation fan is the right size, or you know it’s the occasion for a new one, give the experts at Polestar Plumbing, Heating & Air Conditioning at call at 913-432-3342. We’re here to help you make sure you have a ventilation fan that will drive 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.