"This HeatStar Propane Heater provides efficient, cost-effective heat for loading docks, warehouses, factories, pole barns and more. BTU Output 40,000, Clearance from Corner in. 30, Heating Capability sq. ft. 750, Thermostat Included No, Dimensions L x W x H in. 30 1/4 x 19 1/4 x 12, Blower Included No, Gas Inlet in. 1/2, Blower Power Supply Volts, Amps 110V, Needs Direct Venting No, Oxygen Depletion Sensor No, Clearance from Rear Wall in. 30, Clearance from Side Wall in. 30, Product Type Radiant heat, Igniter Yes. No direct venting required Durable construction Quiet, clean heat Maintenance-free design Includes extra orifice for increasing BTU output Requires 24 Volt thermostat to operate Item# 16342 sold separately"