Inline Fans & Blowers
Vent fans are rated by how many cubic feet of air they circulate in a minute, CFM. To determine the proper CFM that is needed to circulate the air in your space, you will need to calculate the volume of your space. (L x W x H). The ideal refresh rate is every five minutes, so divide the total room volume by five. This will help you determine the proper CFM needed to refresh the air in your room.
12' x 12' x 12' room = 1728 cubic feet.
1728 divided by 5 = 345.6
The example room would need at least a fan pushing 345 CFM to fully exchange the air every 5 minutes.