Cfm Rating For Exhaust Fans

Whether exhausting air or bringing fresh air into a structure the calculation produced should help to figure out the size of fan s required to accomplish the air exchanges needed.

Cfm rating for exhaust fans.

Don t skimp since this should be a one time purchase for most homeowners. Purchase a bathroom fan with the required cfm rating or higher. After calculating your required cfm make sure to check the rating of any fan your purchase. 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.

5 x research source a fan with too low of a rating won t remove moisture effectively while buying a fan with too much power may lead to unnecessary noise as more powerful fans tend to. And a happier marriage. Better quality exhaust fans offer higher cfm s and better motors meaning a longer service life a quieter bathroom. Cfm is key when determining a fan s airflow efficiency.

A cfm of 75 is the minimum number to make a fan efficient. Airflow efficiency is the cfm divided by the watts amount of energy used to run the fan at its highest speed. As a comparison that s roughly as loud as a car idling from about 33 feet away. Panasonic offers their well known whisperceiling fan in various cfm ratings 50 cfm 80cfm 110cfm 150 cfm.

This fan calculator is typically used to calculate the cfm or cubic feet per minute of air exchange that may be desired in a building. It is a bit noisier generating 4 0 sones during operation however. 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 cubic feet per minute cfm is very important.

Based on personal experience i would recommend purchasing the best quality fan you can afford that exceeds your computed cfm value. To calculate the minimum cubic feet per minute rating needed for an exhaust fan multiply the bathroom s length width and height and then multiply that result by 0 13. With an airflow rate of 110 cfm and 0 8 sones sound rating this exhaust fan puts up the kind of performance that s likely to exceed your expectation. This bathroom exhaust fan from air king has a cfm rating of 120 making it perfect for larger bathrooms or as a permanent exhaust fan to promote healthy air circulation in your home.

The final answer is the minimum cfm rating for the fan. You could have a fan that moves a lot of air with a high cfm but does so at a high wattage.