What are industrial blower fan classes?

For industrial centrifugal fans the usual classifications are numbered 1 through 4 for clean air fans. These numbers represent maximum RPM / tip speed limits for each given size, and also help indicate the pressure each fan is capable of achieving.

For other fan designs, there is no universal classification system. What you will find is companies tend to use numbers that correlate with the maximum pressure capability in inches of static pressure. Typical numbers used are 15, 20, 30, 35, 45, and 50.

In general, the lower the number, the lighter duty construction. The higher the number, the heavier construction.

The association that provides guidelines for this is AMCA, however not all fan and blower manufacturers follow their recommendations for classifications since what they offer is boiler plate material. Indventech