Forced Air Furnaces
A natural gas furnace does an excellent job at providing toasty warm air during a cold winter day. Natural gas furnaces can also be converted to propane, however a hybrid heating setup should be considered to lower heating costs by using both gas and electric heating sources.
How It Works
A furnace is comprised of a burner, heat exchanger (metal grid-like object) and a fan motor. When the thermostat registers inside air is too cold, the furnace flame heats the heat exchanger. Then the fan motor pulls air from the home via return air duct(s) and forces the air through the heat exchanger. The cool air absorbs heat energy, and is then sent back into the home!
An Annual Fuel Utilization Efficiency (AFUE) rating is used to show the percentage of fossil fuel that is actually converted into heat energy. Modern condensing gas furnaces with variable speed fan motors and fully modulating flames are able to hit very high AFUE ratings.