"This HeatStar High-Intensity Infrared Propane Heater provides quiet, clean heat for pole barns, factories, warehouses, loading docks and more. U.S.A. Clearance from Corner in. 46, Oxygen Depletion Sensor No, Blower Included No, Thermostat Included No, Clearance from Side Wall in. 46, BTU Output 100,000, Heating Capability sq. ft. 1,200, Product Type Radiant heat, Needs Direct Venting No, Gas Inlet in. 1/2, Dimensions L x W x H in. 60 1/2 x 21 1/2 x 11, Igniter Spark ignition, Clearance from Rear Wall in. 46. No direct venting required Additional burner orfices enables the installer to increase or decrease the heat output Spark ignition heaters ship with 40VA transformer Millivolt control heaters shipped with thermostat Noncorrosive materials are used throughout heater construction"