CFM Rating
The CFM rating of a vent fan measures the volume of air it can move in cubic feet per minute. The higher the CFM rating, the more powerful the fan and the more air it can remove from the bathroom.
For a typical bathroom, a CFM rating of 50 to 100 is sufficient. However, if the bathroom is large or has a high moisture level, a higher CFM rating may be necessary.
Noise Level
The noise level of a vent fan is measured in sones. The lower the sone rating, the quieter the fan.
