A gas burner (see Figure 2-1) is a device for supplying gas, or a mixture of gas and air, to the combustion area. Those used in residential and light commercial heating are most commonly high-pressure, gun-type burners. Only those gas burners approved by the American Gas Association (AGA) should be used in a heating system.
Gas is used as a heating fuel in both urban and rural areas. Manufactured, natural, and bottled gas are the three types used as heating fuels. Each of these gases has different combustion characteristics and will have different heat values when burned. Because of this, a gas burner must be adjusted for each gas fuel, particularly when changing from one type to another. The principal types of bottled gas used as heating fuels are propane and butane. Bottled gas is frequently called LPG (liquefied petroleum gas) and is widely used as a heating fuel in rural areas.