You multiply length times width times height.
Exhaust fan size for toilet.
An effective bathroom fan should be capable of replacing the entire volume of air 8 times per hour or every 7 5 minutes.
Check the size of the exhaust port on the fan to make sure it fits your ductwork if applicable.
If your bathroom has a toilet or shower area enclosed by a door it s a good idea to install a separate exhaust fan for that area.
For a standard 10ft by 10 ft bathroom with an 8 ft ceiling you will need an exhaust fan capable of 106 67 cfm.
The formula to calculate bathroom exhaust fan size reads as follows.
If the enclosed space is small a 50 cfm fan should suffice.
Double hanger bar system for ideal positioning.
To arrive at your required cfm simply divide your bathroom s volume by 7 5.
Includes built in 6w led light.
45 watt 4 duct connector.
Determine the required cfm for your bathroom fan.
But o brian suggests a simpler rule of thumb.
1007 rpm fan speed.
You now need to multiply 960 x 15.
For bathrooms less than 100 square feet you can just go with 1 cfm for every square foot of floor area he says.
Cubic volume 7 5 cfm necessary.
The minimum requirements say that this air should be changed 15 times an hour.
10 feet x 12 feet x 8 feet that computes to 960 cubic feet of air in the room.
Here s how we get this number.
For example if your bathroom is 80.
10ft 10ft 8ft 7 5 106 67 cfm.
120 cfm and 1 2 sones.
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.
Otherwise use the appropriate calculation based on the room size.