What Size Exhaust Fan Do I Need For My Bathroom

The following table does lots of the math for you.

What size exhaust fan do i need for my bathroom. The formula to calculate bathroom exhaust fan size reads as follows. Moist air from showers tubs and other fixtures in a bathroom can accumulate on bathroom surfaces leading to rot and peeling paint and providing a good environment for mold and mildew growth. Bathroom fans improve indoor air quality by venting moist air quickly outside which eliminates problems associated with high humidity like mold and mildew growth steamy mirrors and peeling wallpaper and paint. The minimum allowed fan size is 50 cfm so if your bathroom is for example only 42 square feet you still need a 50 cfm fan.

Bathroom fan exhaust size calculator. Tam asks what size exhaust fan should we use in our small bathroom if your bathroom has an 8 ceiling the cubic feet per minute cfm rating for your fan should be as high or higher than the number of square feet in the room. A bathroom fan is an essential piece of hardware in any indoor bathroom without a window. A large bathroom with a jetted tub a toilet and a shower a common configuration in new homes would need a 200 cfm ventilation fan such as the broan l200 ventilation fan available from.

Why you need to have the proper size extractor fan. A diameter of 4 inches. This guide will help you understand how to choose the right size and type of bathroom fan. Higher ceilings would require a larger fan.

Click here to get free fast bids from local contractors that install ventilation fans. This keeps the moisture from the shower bath or sink from encouraging mold growth. Sizing for large bathrooms for bathrooms over 100 square feet exhaust fans can be sized according to the number of fixtures in the room. The fan pulls air out of the bathroom and allows fresh air to be drawn in.

Simply enter the dimensions of your bathroom in the calculator below to determine the minimum size vent fan you need for the bathroom in your home. Cubic volume 7 5 cfm necessary. Handy table for fan values. Never vent a bathroom fan directly into an attic it must always vent outside.

Bathroom extractor fans are mandatory in any bathroom without a window and still highly recommended in bathroom with windows. When installing a vent fan make sure there s at least a 1 2 gap under the bathroom door to allow fresh air to enter the room when the fan is running. Check the size of the exhaust port on the fan to make sure it fits your ductwork if applicable. All you need to do is calculate the square feet of a room and the table tells you the cfm for either a kitchen or bathroom.