Plenum Fan Wheel Type Backward-Curved Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 27 3/8 in Airflow @ 0.250 in SP 8 026 cfm Airflow @ 0.500 in SP 7 612 cfm Airflow @ 0.750 in SP 7 162 cfm Airflow @ 1.000 in SP 6 602 cfm Airflow @ 1.250 in SP 5 871 cfm Airflow @ 1.500 in SP 4 684 cfm Maximum Inlet Air Temperature 104 Degrees F Shaft Diameter 1 5/8 in Bearing Type Ball