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.
Exhaust fan size for bathroom.
To arrive at your required cfm simply divide your bathroom s volume by 7 5.
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 size of your bathroom can help determine how many cfms you need.
Here s how we get this number.
For bathrooms between 50 and 100 square feet estimate approximately 1 cfm per square foot.
But o brian suggests a simpler rule of thumb.
Small room bath fans perfect for a modest sized bath or powder room.
For example if your bathroom is 80.
Bathroom select a fan with a 50 to 80 cfm rating.
Tam asks what size exhaust fan should we use in our small bathroom if your bathroom has an 8 ceiling the cubic feet per minute cfm rating for your fan should be as high or higher than the number of square feet in the room.
If your bathroom is larger than 100 square feet tally the cfm requirements for the individual fixtures to estimate your needs.
Some manufacturers recommend the number of cfms based on square feet or cubic feet.
An effective bathroom fan should be capable of replacing the entire volume of air 8 times per hour or every 7 5 minutes.
For bathrooms less than 100 square feet you can just go with 1 cfm for every square foot of floor area he says.
A 50 square foot or smaller bathroom needs a 50 cfm fan.
Length x width square feet length x width x height cubic feet.
Choose a fan that can move at least 1 cfm per square foot of room.
Sizing for large bathrooms for bathrooms over 100 square feet exhaust fans can be sized according to the number of fixtures in the room.
Determine the required cfm for your bathroom fan.
Bathroom select a fan with a 50 to 80 cfm rating.
Choose a fan that can move at least 1 cfm per square foot of room.
Broan surfaceshield vital vio powered exhaust fan w led light antibacterial light.
10ft 10ft 8ft 7 5 106 67 cfm bathroom fan exhaust size calculator.
Higher ceilings would require a larger fan.
Small room bath fans perfect for a modest sized bath or powder room.
Read on to find out more.
For example for a 50 79 sq.