What is gas heat?

If it is a gas furnace, the heat is supplied by the burning of natural gas. A mixture of gas and air flows into the burner and is ignited by the pilot. Combustion occurs, and warm air from the burner flame rises to fill a chamber known as a heat exchanger. The heat exchanger becomes hot. Office air passing around the heat exchanger absorbs that warmth, continues into the air ducts and the heat is distributed through the business. The by-products of combustion pass upward through a venting system and escape through a vent in the roof.