Central Furnace

Energy Upgrade California Photos by Noah Berger Photo Copyright Purchased by MIG/EUC Model Release Obtained for All SubjectsFurnaces work by burning natural gas to create heat through a heat exchanger. Then, air is blown over the heat exchanger through your home’s ducts, and into your house’s rooms. Energy efficiency for a furnace can be determined by its Annual Fuel Utilization Efficiency (AFUE). Choose an energy efficient model of 92 percent AFUE or higher.

• Many older furnaces have an AFUE of 60 percent. This means that for every $100 spent on heating costs, only $60 are actually used efficiently for heating your home—the other $40 are wasted. An AFUE rating of 92 percent means that only $8 would be wasted.