What Is a Natural Draft Furnace?
Natural draft furnaces are an older kind of furnace, now regarded as inefficient with an estimated efficiency score between 65 and 70 percent. Before high efficiency units were readily available, natural draft furnaces were common and are still found in many homes, although some of these units have been retrofitted with new parts that improve their performance.
An Uplifting Experience
A natural draft furnace is one which utilizes natural atmospheric pressure to force the waste gasses of combustion outside during the ventilation system. Since the fuel in the furnace burns, it creates hot air in addition to combustion byproducts, such as carbon monoxide and nitrogen dioxide. Hot air naturally rises, lifting the combustion byproducts along with it. As the hot air rises through the vent, cooler and denser air from outside the furnace flows in, developing a pure draft which pushes air through the system and assists in combustion.