What Size Bathroom Vent Fan Do I Need

The home ventilating institute recommends that every bathroom have an adequate ventilation system that changes the air eight times an hour.

What size bathroom vent fan do i need. 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. If you do something wrong that s a stinky mess sub floor damage waiting to happen. You do not want to diy a toilet. 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.

Use the room size to determine the necessary cubic feet per minute cfm rating of the fan. The cfm of the bathroom will account for the toilet. Ft in the room. All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans.

While it won t be as effective as a fan with a proper cfm you can install a smaller fan directly above these fixtures for instance a 50 cfm fan above the toilet in order to satisfy a minimum need for ventilation. If you are trying to replace a toilet call a plumber. Consider a bathroom that is 10ft. In those areas ventilation in bathrooms is required but it can be from a window or fan your choice.

So for example if your bathroom is 54 metres square you will need a 54m3 hr fan. Sizing for large bathrooms for bathrooms over 100 square feet exhaust fans can be sized according to the number of fixtures in the room. Each toilet shower and bath tub needs about 50 cfm each while a jet tub needs 100 cfm. Surprisingly bathroom fans are not required by some building codes.

A fan that s too small won t remove moisture and odors efficiently and will need to run longer increasing wear on the motor. What is the minimum throughput rating for a vent fan. You shouldn t need to calculate it by toilet size. The cfm rating measures the volume of air the fan moves.

Make sure the fan you choose is powerful enough to ventilate your bathroom. What minimum size cfm vent fan do i need per cubic foot of bathroom. According to hvi an easy approximation is to provide. In order to know what size bathroom exhaust fan you need refer to the cm3 cubic metres squared measurement of your fan.

Bathroom vent fans are rated by the cubic feet per minute cfm of air they move and should be sized to replace the air in the room at least eight times an hour.