heat air using electricity, natural gas, or other fuel, and distribute the heated air throughout a home using ductwork. Upgrading to a premium efficiency furnace can save energy and money.
A furnace is rated by its Annual Fuel Utilization Efficiency (AFUE) score. The AFUE measures how efficiently a furnace uses its fuel. For example, an AFUE of 95 percent means that 95 percent of the energy in the furnace's fuel becomes heat for the home (the other 5 percent escapes up the chimney or elsewhere).
Federal, local, or utility programs may offer incentives
for installing certain energy-efficient devices in your home.