Plenum Fan Wheel Type Backward-Curved Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 27 3/8 in Airflow @ 0.000 in SP 9 641 cfm Airflow @ 0.250 in SP 9 296 cfm Airflow @ 0.500 in SP 8 948 cfm Airflow @ 0.750 in SP 8 572 cfm Airflow @ 1.000 in SP 8 167 cfm Airflow @ 1.250 in SP 7 682 cfm Airflow @ 1.500 in SP 7 097 cfm Airflow @ 1.75 in SP 6 382 cfm Airflow @ 2.000 in SP 5 181 cfm Maximum Static Pressure 2 in wc