This 200000 BTU heater is just like your home oil or gas burning furnace with a chimney. It provides 100% clean dry air which eliminates the chance of carbon monoxide being pumped into your work space. It runs on #1 or #2 diesel or kerosene & burns approximately 1.30 gallons per hour. With its large 42 gallon fuel tank it will run for 30 hours +/- between fills. It comes complete with (1) thermostat & (1) 12″ x 25″ duct. Additional 25′ ducts are available if more length is required.