Plenum Fan Wheel Type Backward-Curved Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 13 1/2 in Airflow @ 0.000 in SP 2 325 cfm Airflow @ 0.250 in SP 2 233 cfm Airflow @ 0.500 in SP 2 141 cfm Airflow @ 0.750 in SP 2 035 cfm Airflow @ 1.000 in SP 1 921 cfm Airflow @ 1.250 in SP 1 780 cfm Airflow @ 1.500 in SP 1 630 cfm Airflow @ 1.75 in SP 1 456 cfm Airflow @ 2.000 in SP 1 213 cfm Maximum Static Pressure 2 in wc