Furnaces come typically as gas, electric or oil powered and provide warm air in the winter. Furnace heating ability is measured with an Annual Fuel Utilization Efficiency (AFUE) percentage. Remember, a higher AFUE percentage indicates a more efficient furnace.
A gas furnace uses natural gas, although some models can be converted to utilize propane. An oil furnace uses heating oil. An electricity source is required to run the control systems, blower and some accessories.
The basic components of a furnace are:
- A burner, through which gas (natural or propane) or oil is delivered and burned.
- A heat exchanger, where the heat produced from the burning gas is transferred to the air distribution system.
- Ductwork to transfer the heated air throughout the home.
- A flue or vent pipe, to exhaust byproducts of combustion (such as water vapor and carbon dioxide) to the outside.