Commercial Restroom Exhaust Fan Sizing

This exhaust air can be routed either to the roof using ductwork and a roof vent or to the side.

Commercial restroom exhaust fan sizing.

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. This section discusses the minimum exhaust capacity of the exhaust fan. 10ft 10ft 8ft 7 5 106 67 cfm. Sizing for large bathrooms for bathrooms over 100 square feet exhaust fans can be sized according to the number of fixtures in the room.

The formula to calculate bathroom exhaust fan size reads as follows. Here s how we get this number. Determining the best location for a fan depends on the airflow pattern desired and the physical characteristics of the building. For a standard 10ft by 10 ft bathroom with an 8 ft ceiling you will need an exhaust fan capable of 106 67 cfm.

Greenheck is the leading supplier of air movement control and conditioning equipment including fans. Cubic feet per minute cfm. The minimum allowed fan size is 50 cfm so if your bathroom is for example only 42 square feet you still need a 50 cfm fan. A commercial restroom will require air to be changed 8 12 times an hour depending on the size of the facility and your local code.

In our example restroom the exhaust rate at 0 cfm 3 s per plumbing xture ould be 420 cfm 210 s figure 2 don from 0 cfm 280 s based on 10 ach f. It may seem to make sense to exhaust above each xture. 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. 50 cubic feet per minute cfm intermittent or 20 cfm continuous.

By surveying the building structure and visualizing how the air should flow the place to locate the fan usually becomes evident. Cubic volume 7 5 cfm necessary. Sizing and finding high quality low maintenance exhaust and air movement equipment can save money for agencies and business owners. Commercial and industrial ventilation can be expensive to install or update and finding the right type and size of fan will keep companies and industries in compliance with codes and regulations.

To arrive at your required cfm simply divide your bathroom s volume by 7 5. 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. The illustration above demonstrates the use of a ceiling exhaust fan mounted in the rest room exhausting the stale air. Number of exhaust grilles the design in f includes four exhaust grilles one over each ater closet and one over the bank of urinals.