Combustion Air Intake System For Fuel Type Natural Gas and Oil Maximum Appliance BtuH Input 1 803 000 BtuH Maximum Airflow 1 625 cfm Nameplate Voltage 120V AC Compatible System 120V Appliance Inlet Diameter 10 in Outlet Diameter 10 in Oil Appliance BtuH Input Max of 1.2 M or 12.75 GPH Natural Gas Appliance BtuH Input Up to 1 803 000 BtuH Minimum Vent Pipe Diameter 10 in Maximum Vent Pipe Diameter 14 in Overall Height 20 1/8 in Overall Length 16 in Overall Width 16 1/8 in