Exhaust Fan Cfm Chart

Here s how we get this number.

Exhaust fan cfm chart.

Airflow efficiency is the cfm divided by the watts amount of energy used to run the fan at its highest speed. 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 second fan is 150cfm with the ability to have a 4 or 6 vent pipe attached. You could have a fan that moves a lot of air with a high cfm but does so at a high wattage.

Learning how to calculate cfm for a bathroom fan will help you purchase the right size fan for your space. The formula to calculate bathroom exhaust fan size reads as follows. 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.

For a standard 10ft by 10 ft bathroom with an 8 ft ceiling you will need an exhaust fan capable of 106 67 cfm. 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. The effectiveness of the fan will be rated in cfm or cubic feet per minute of air moved. 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. Cubic volume 7 5 cfm necessary. Bathroom fan exhaust size calculator. 10ft 10ft 8ft 7 5 106 67 cfm.