Plenum Fan Wheel Type Backward-Curved Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 30 1/2 in Airflow @ 0.250 in SP 9 221 cfm Airflow @ 0.500 in SP 8 656 cfm Airflow @ 0.750 in SP 7 989 cfm Airflow @ 1.000 in SP 7 135 cfm Airflow @ 1.250 in SP 5 827 cfm Maximum Inlet Air Temperature 104 Degrees F Shaft Diameter 1 5/8 in Bearing Type Ball Sound Level 14.6 sones @ 1.500 in SP and 5 ft 18.8 sones @ 0.250 in SP and 5 ft Frame Material Steel