For a standard 10ft by 10 ft bathroom with an 8 ft ceiling you will need an exhaust fan capable of 106 67 cfm.
What size cfm exhaust fan for bathroom.
Enter bathroom width ft.
A fan s ability to move air is measured in cubic feet per minute cfm.
10ft 10ft 8ft 7 5 106 67 cfm.
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.
Suggested cfm for the bathroom is based on cycling all the air in the bathroom 8 times per hour.
Determine the size of your bathroom with this formula.
Here s how we get this number.
The formula to calculate bathroom exhaust fan size reads as follows.
The result is the cfm or cubic feet per minute rating required for your bathroom fan.
Cubic volume 7 5 cfm necessary.
If your bathroom has an 8 ceiling the cfm rating for your fan should be as least as high as the number of square feet 5 x 7 35 sq.
A fan should have a cfm rating high enough to replace the air in your bathroom at a rate 8 times per hour.
Learning how to calculate cfm for a bathroom fan will help you purchase the right size fan for your space.
The bath fan calculator is standard guide to help you find the minimum fan rating for your specific bathroom.
Toilet 50 cfm shower stall 50 cfm whirlpool 100 cfm 200cfm bathroom exhaust fan.
Enter bathroom height step 4.
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.
Bathroom fan exhaust size calculator.
For example if your bathroom is 80 square feet you ll need an 80 cfm fan such as the broan smartsense 80 cfm ventilation fan available from supplyhouse.
Enter bathroom length ft.
The effectiveness of the fan will be rated in cfm or cubic feet per minute of air moved.
Ft in the room.
The bigger your bathroom the higher the cfm rating you ll need.
Bathroom vent fans serve an important function by removing humid air from your home to prevent mold and mildew from forming.
Vent fans are rated by the number of cubic feet of air they move per minute cfm and it s important to buy a large enough fan for the size of your bathroom.
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.
The cfm represents the airflow required to completely exchange the air in your bathroom 8 times in one hour.
Sizing for large bathrooms for bathrooms over 100 square feet exhaust fans can be sized according to the number of fixtures in the room.