Blower Wheel Type Backward-Inclined Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 30 in Airflow @ 0.250 in SP 12 851 cfm Airflow @ 0.500 in SP 12 474 cfm Airflow @ 0.750 in SP 12 096 cfm Airflow @ 1.000 in SP 11 712 cfm Airflow @ 1.250 in SP Not Applicable Airflow @ 1.500 in SP 10 914 cfm Airflow @ 2.000 in SP 10 039 cfm Airflow @ 2.500 in SP 9 012 cfm Airflow @ 3.000 in SP 7 608 cfm Airflow @ 3.500 in SP Not Applicable