What Size Should My Bathroom Ventilation Fan Be? 07/28/2017Average tasks like showering, bathing and shaving can put home-harming humidity into the air in your Ballwin home. There’s good news though—a modest bathroom ventilation fan can protect you from distorted wood, mold growth, broken drywall and other issues 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? Holiday Heating & Air Conditioning is here to answer your questions. Today’s bathroom ventilation fans are small and sleek and they run more quietly and effectively than ever before. You’ll find a hefty range of selections, from average fans that will get the job done to fans with integrated 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 select from, the most imperative feature 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 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 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 use HGTV’s guidance 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 not sure if your bathroom ventilation fan is the proper size, or you know it’s time for a new one, give the professionals at Holiday Heating & Air Conditioning at call at 636-206-4250. We’re here to help you guarantee you have a ventilation fan that will drive hard to guard your home and keep it comfy. You can even set up an appointment with us online if that’s the most straightforward for you.