Plenum Fan Wheel Type Backward-Curved Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 22 in Airflow @ 0.000 in SP 7 077 cfm Airflow @ 0.250 in SP 6 863 cfm Airflow @ 0.500 in SP 6 649 cfm Airflow @ 0.750 in SP 6 435 cfm Airflow @ 1.000 in SP 6 179 cfm Airflow @ 1.250 in SP 5 913 cfm Airflow @ 1.500 in SP 5 614 cfm Airflow @ 1.75 in SP 5 269 cfm Airflow @ 2.000 in SP 4 912 cfm Airflow @ 2.500 in SP 3 990 cfm Maximum Static Pressure 2 1/2 in wc