Cfm For Bath Fan

Standard fan sizing applies to bathrooms that are 100 square feet or less.

Cfm for bath fan.

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. To arrive at your required cfm simply divide your bathroom s volume by 7 5. Enter bathroom width ft. Bathroom vent fans are rated for the amount of air they can move measured in cubic feet per minute or cfm.

Enter bathroom height step 4. The result is the cfm or cubic feet per minute rating required for your bathroom fan. 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. Standard fan sizing.

Press calculate minimum suggested bath fan cfm. Bathroom vent fans serve an important function by removing humid air from your home to prevent mold and mildew from forming. A fan that s too small won t remove moisture and odors efficiently and will need to run longer increasing wear on the motor. A 50 square foot or smaller bathroom needs a 50 cfm fan.

The bath fan calculator is standard guide to help you find the minimum fan rating for your specific bathroom. An effective bathroom fan should be capable of replacing the entire volume of air 8 times per hour or every 7 5 minutes. In general for rooms with 8 foot ceilings. Enter bathroom length ft.

For bathrooms between 50 and 100 square feet estimate approximately 1 cfm per square foot. The rule of thumb is that you need at least 1 cfm per square foot of room area. The cfm represents the airflow required to completely exchange the air in your bathroom 8 times in one hour.