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 Phoenix home. There’s good news however—a straightforward bathroom ventilation fan can save you from distorted wood, mold growth, cracked 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 proper size? Are they as noiseless and energy efficient as they could be? Dial One Mears Air Conditioning & Heating Inc is here to answer your questions. Today’s bathroom ventilation fans are small and smooth and they operate more quietly and effectively than ever before. You’ll find a large range of choices, from simple fans that will get the job done to fans with fitted heat lamps, motion sensors and heat-exchanger ventilation that helps prevent warmed air from escaping through your ventilation. While you can find a lot of bells and whistles to pick from, the most critical aspect of your fan is whether or not it’s large 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 replace 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. Thus, if your bathroom is 5 feet by 8 feet, a CFM rating of 40 would be satisfactory. 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 follow HGTV’s guidance for bathrooms larger than 100 square feet – determine 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 come to the point for a new one, give the pros at Dial One Mears Air Conditioning & Heating Inc at call at 602-997-5701. We’re here to help you ensure 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 easiest for you.