Higher ceilings would require a larger fan.
Room exhaust fan sizing.
If the room is 75 square feet or smaller your ceiling fan should be 36 inches or less in diameter.
Standard fan sizing applies to bathrooms that are 100 square feet or less.
Sizing an exhaust fan use this table to calculate the cubic feet per minute cfm capacity needed for an exhaust fan in a specific room.
Learning how to calculate cfm for a bathroom fan will help you purchase the right size fan for your space.
Once the exhaust fan application is known keep in mind these four parameters to choose the right one for the job.
Measure the room s length and width then multiply them together.
You now need to multiply 960 x 15.
The rule of thumb is that you need at least 1 cfm per square foot of room area.
The minimum requirements say that this air should be changed 15 times an hour.
Exhaust fan must be strong enough to restore the bathroom with fresh air every 7 1 2 minutes or 8 times an hour.
Bathroom vent fans are rated for the amount of air they can move measured in cubic feet per minute or cfm.
This can lead to serious problems including warped cabinetry fogged mirrors mold and or mildew growth.
That computes to 960 cubic feet of air in the room.
Standard fan sizing.
Before you install bathroom kitchen or garage exhaust fans start here to determine what you need to proceed for.
This fan calculator is typically used to calculate the cfm or cubic feet per minute of air exchange that may be desired in a building.
Read on to find out more.
Refer to the suggested limits for room loudness chart below to determine the acceptable sone range for the application.
Whether exhausting air or bringing fresh air into a structure the calculation produced should help to figure out the size of fan s required to accomplish the air exchanges needed.
This page is designed to be a general guide for selecting an exhaust fan based on the size of the room and the type of application the fan will be used for.
To be effective a bathroom fan needs to be powerful enough to completely replace the air in the room about 8 times every hour.
A ventilation fan should meet at least the minimum standard cfm to provide proper exhaust.
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.
Watch these helpful videos about exhaust fans and how to vent them out.
All you need to do is select the application from the dropdown enter the size of the room and we will provide you with a general capacity range m3 hr that you should be looking to achieve from the extraction fan.
A fan that is too small will not effectively remove moisture from the room.
As a general guideline choose a fan that has a sone rating within the range specified.
This is the industry standard.
The effectiveness of the fan will be rated in cfm or cubic feet per minute of air moved.
