Airfoil Centrifugal Fan, SWSI Centrifugal Fans - SWSI & DWDI SWSI Centrifugal Fans BAE-SW - Airfoil BAF-SW - Airfoil BC-SW - Backward Inclined CBA-SW - Airfoil CB-SW - Backward Inclined DWDI Centrifugal Fans BAE-DW - Airfoil BAF-DW - Airfoil BC-DW - Backward Inclined High Volume & Pressure BCS - Backward Curved BCSF - Backward Curved (Composite) Dust Collection TCBI - Backward Inclined, Direct Drive