A fan should have a cfm rating high enough to replace the air in your bathroom at a rate 8 times per hour.
Cfm rating bathroom exhaust fan.
5 x research source a fan with too low of a rating won t remove moisture effectively while buying a fan with too much power may lead to unnecessary noise as more powerful fans tend to.
Purchase a bathroom fan with the required cfm rating or higher.
The duct fan is rated 120 cfm free air.
Bathroom extractor fans are mandatory in any bathroom without a window and still highly recommended in bathroom with windows.
1 panasonic fv 11vq5 whisperceiling bathroom exhaust fan review.
The cfm represents the airflow required to completely exchange the air in your bathroom 8 times in one hour.
After calculating your required cfm make sure to check the rating of any fan your purchase.
The exhaust fan removes moisture and humidity from your bathroom.
Otherwise use the appropriate calculation based on the room size.
A bathroom exhaust fan that is rated 50 cfm is ok to use in bathrooms that are 50 square feet or smaller.
Therefore a bathroom with an area of 70 square feet needs a fan with a minimum cfm rating of 70.
Fan ratings typically run between 50 and 110 cfm.
With larger rooms at least one cfm for each square foot is required.
Why you need to have the proper size extractor fan.
The bigger your bathroom the higher the cfm rating you ll need.
So if you have a bathroom that is 12 feet long 15 feet wide and 10 feet tall then it has a volume of 1800 cubic feet 12 x 15 x 10 and a cfm of 240.
Its cfm per sone rating is 0 0800 about 20 times less efficient on a cfm per sone basis than the whisperquiet and higher than most other bathroom fans on the market.
If the enclosed space is small a 50 cfm fan should suffice.
A fan s ability to move air is measured in cubic feet per minute cfm.
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.
A bathroom that is 50 square feet or less needs a 50 cfm fan.
A second fan may be needed.
I installed a 5 duct fan for bathroom exhaust the total length of duct to outside is less than 6 ft.
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.
Another bathroom exhaust fan of the type purchased by commercial establishments pulls 470 cfm at the cost of 8 0 sones.
Length x width x height x 0 13 minimum.
Determine the size of your bathroom with this formula.
The cfm number should be equal to or higher than the listed square footage of the bathroom an exhaust fan is being installed in i e.
The appropriate size fan for a bathroom can replace the room s air.