Blower Wheel Type Radial Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 29 5/8 in Airflow @ 1.000 in SP 8 541 cfm Airflow @ 2.500 in SP Not Applicable Airflow @ 4.000 in SP 12 543 cfm Airflow @ 5.000 in SP 11 870 cfm Airflow @ 6.000 in SP 11 200 cfm Airflow @ 7.000 in SP 10 534 cfm Airflow @ 8.000 in SP 9 870 cfm Airflow @ 9.000 in SP 9 205 cfm Airflow @ 10.00 in SP 8 541 cfm Airflow @ 11.00 in SP 7 867 cfm