Exhaust Fan Cfm Chart

Bathroom fan exhaust size calculator.

Exhaust fan cfm chart.

You could have a fan that moves a lot of air with a high cfm but does so at a high wattage. If i can find a y pipe with a 4 and a 6 entry what size should the exit pipe be. A cfm of 75 is the minimum number to make a fan efficient. 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.

Cfm is key when determining a fan s airflow efficiency. To be effective a bathroom fan needs to be powerful enough to completely replace the air in the room about 8 times every hour. If you have any questions regarding cfm s air exchanges needed the calculator or which exhaust and or supply fans may be right for your building please call us at 866 727 1060. If you are not sure what kind of cfm s may be needed for your type of facility please refer to the commercial industrial applications chart below.

Learning how to calculate cfm for a bathroom fan will help you purchase the right size fan for your space. 10ft 10ft 8ft 7 5 106 67 cfm. Here s how we get this number. Cubic volume 7 5 cfm necessary.

Sizing for large bathrooms for bathrooms over 100 square feet exhaust fans can be sized according to the number of fixtures in the room. For a standard 10ft by 10 ft bathroom with an 8 ft ceiling you will need an exhaust fan capable of 106 67 cfm. 100 cfm fan with a 4 exhaust port and back flow flap. The formula to calculate bathroom exhaust fan size reads as follows.