Goodman GMH80403AN 80% AFUE Two-Stage (Convertible), Multi-Speed Multi-Position Gas Furnaces feature a patented aluminized-steel tubular heat exchanger and durable Silicon Nitride Hot Surface Ignition system. This furnace is run-tested for heating or combination heating/cooling applications. With a heavy-gauge, reinforced, insulated steel cabinet and durable baked enamel finish, this unit can be installed in a variety of locations.