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 Elmhurst home. There’s good news though—a simple bathroom ventilation fan can keep you from distorted 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 correct size? Are they as soft and energy efficient as they could be? Alan Heating Air Conditioning, Inc. 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 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 getting out through your ventilation. While you can find a lot of bells and whistles to choose from, the most imperative aspect 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 transfer, a bathroom ventilation fan should be able to replace 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 easy, you can use HGTV’s tips 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 unclear if your bathroom ventilation fan is the correct size, or you know it’s time for a new one, give the pros at Alan Heating Air Conditioning, Inc. at call at 630-833-1100. We’re here to help you make sure you have a ventilation fan that will work hard to care for your home and keep it comfy. You can even schedule an appointment with us online if that’s easiest for you.