For bathrooms less than 100 square feet you can just go with 1 cfm for every square foot of floor area he says.
Exhaust fan size for toilet.
By simply inputting into the calculator the dimensions of your room and the type of room application for the fan the calculator will provide you with a suggested general capacity range in cubic metres per hour m3 hr to help narrow down your exhaust.
If the enclosed space is small a 50 cfm fan should suffice.
A diameter of 4 inches is common for exhaust ducts but some high cfm fans fit a 6 inch diameter duct.
10ft 10ft 8ft 7 5 106 67 cfm.
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.
You can upgrade to a larger diameter duct for greater efficiency or you can use an adapter reducer often included with the fan to fit the smaller duct.
Determine the required cfm for your bathroom fan.
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.
But o brian suggests a simpler rule of thumb.
Here s how we get this number.
How to choose one.
Because toilets are usually in small rooms a small quiet exhaust fan should do the trick.
Why you need to have the proper size extractor fan.
Industry experts recommend 60 cfm to 80 cfm for small bathrooms and 200 to 300 cfm for a large bathroom with a steam generator.
The fan model its size and cfm rating or the required or design flow rate in cfm from your local code such as 60 or 80 cfm.
Of course this depends on your circumstances so we recommend using our simple exhaust fan calculator to decide which fan you need.
Cubic volume 7 5 cfm necessary.
With a power level of 70 cubic feet per minute cfm this fan will handle bathrooms up to 70 square feet in size.
This fan is described as a sanity saver by homeowners fed up with noisy bathroom exhaust fans.
The calculator on this page is provided as a general guide designed to help you select an exhaust fan which may be suitable for your needs.
The room s size measured in m3 is the most important factor to determine which exhaust fan is suitable for your toilet.
A second fan may be needed.
The formula to calculate bathroom exhaust fan size reads as follows.
To arrive at your required cfm simply divide your bathroom s volume by 7 5.
Just remember that the fan needs airflow to do its job.
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.
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.
The vent material smooth vs.
Bathroom fan exhaust size calculator.