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 8 390 cfm Airflow @ 0.250 in SP 8 210 cfm Airflow @ 0.500 in SP 8 029 cfm Airflow @ 0.750 in SP 7 849 cfm Airflow @ 1.000 in SP 7 668 cfm Airflow @ 1.250 in SP 7 465 cfm Airflow @ 1.500 in SP 7 241 cfm Airflow @ 1.75 in SP 7 017 cfm Airflow @ 2.000 in SP 6 781 cfm Airflow @ 2.500 in SP 6 199 cfm Airflow @ 3.000 in SP 5 565 cfm