There are 8 basic types of blower wheels or centrifugal impellers used in industrial blowers. They are:

1. Shrouded Radial Blade
2. Open Radial Blade
3. Open Paddle Wheel
4. Backward Inclined
5. Backward Curved
6. Airfoil Blade
7. Forward Curved Multi-vane (Squirrel Cage)
8. Backward Curved Radial

Type 1, Shrouded Radial Blade blower wheels are designed to deliver higher pressures for pressurizing, blow-off systems and long duct or pipe runs.
Available in Models PB, SPB, PBS, RBE and some HP-Series II blowers.

Type 2, Open Radial Blade with Back Plate blower wheels are designed for conveying powdery or granular material and long stringy paper trimmings or fibers.
Available in Models PB, SPB, PBS and RBE blowers.

Type 3, Open Paddle Wheel is primarily for conveying powdery or granular material.
This wheel type is not available from Cincinnati Fan.

Type 4, Backward Inclined blower wheels are available with a flat blade design. These wheel types are commonly used for general ventilation, forced cooling at higher pressures and in dust collection systems where the fan is on the clean air side of the dust collector.
Available in Models HDBI, SQBI, and CPF blowers.

Type 5, Backward Curved blower wheels provide high efficiency and low noise. They are typically used for general ventilation, dust collection where the fan is on the clean side of the dust collector, combustion air, and drying.
Available in Models HDBI and CPF blowers.

Type 6, Airfoil wheels incorporate a blade design with the cross section of an airplane wing. They are the most efficient design for moving large volumes of air. They are commonly used for ventilation, forced cooling at higher pressures, and on dust collectors, where the fan is on the clean side of the collector.
Available in Models HDAF, SQAF, and CPAF blowers.

Type 7, Forward Curve Multi-vane blower wheels are for moving large volumes of air at lower pressures. Typically selected for general ventilation or forced cooling at slower speeds.
Available in Models LM and LMF blowers.

Type 8, Backward Curved Radial blower wheels are a modified version of the Open Radial Blade wheel. It is designed to expand the performance ratings of open radial bladed wheels in some direct driven fans. In some cases, it can be used to convey granular material but should not be used to convey powdery or stringy material.
Available in Models PB, SPB and PBS blowers.