# Calculate Bathroom Exhaust Fan Cfm

### An effective bathroom fan should be capable of replacing the entire volume of air 8 times per hour or every 7 5 minutes.

Calculate bathroom exhaust fan cfm. Bath fan cfm calculator. For example a bathroom with a volume of 1000 cubic feet 28 3 cubic meters needs a fan capable of moving 1000 7 5 or 133 cfm 3 8 cubic meters per minute. Determine the required cfm for your bathroom fan. I installed a 5 duct fan for bathroom exhaust the total length of duct to outside is less than 6 ft.

Remembering that the recommended ach for bathrooms is 8 the exhaust fan needs to ventilate 504 cubic feet x 8 which equals 4 032 cubic feet in one hour. The cfm represents the airflow required to completely exchange the air in your bathroom 8 times in one hour. So divide 4 032 by 60 for minutes in an hour for the desired cfm rating for the exhaust fan which in this case is rounded up to 68. The fan won t even push the damper open even with the spring on the exhaust damper removed.

For standard square or rectangular bathrooms. How to size an exhaust fan for a bathroom measure the dimensions of your bathroom. Building code does not specify bathroom vent locations but in any size bathroom it is the most logical to install it over or as close as possible to the plumbing fixture that requires it. The result is the cfm or cubic feet per minute rating required for your bathroom fan.

Toilet 50 cfm shower stall 50 cfm whirlpool 100 cfm 200cfm bathroom exhaust fan. To arrive at your required cfm simply divide your bathroom s volume by 7 5. The duct fan is rated 120 cfm free air. With this number divide it by multiply it by 0 1 to 1 to get you estimated cfm.

How to calculate cfm cfm calculation formula in general to calculate cfm for your industrial exhaust application you need to know the total floor area of your space. Use a tape measure to measure the length width and height of your bathroom. For example a 1000 square foot area may need a cfm exhaust fan of 1000 0 1 100 or 1000 1 1000. Divide the volume of your bathroom in feet by 7 5.

### Bqnu 70 Cfm Bathroom Fan With Light Bathroom Fan Light Exhaust

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