Goodman 100 000 BTU 80% AFUE Upflow/Horizontal Gas Furnace model GMH81005CN Operates as a natural gas furnace with the provision being converted to a propane furnace using an optional propane conversion kit (not included) Aluminized- steel tubular, corrosion-resistant furnace heat exchanger Reliable, energy-efficient hot surface ignition system with the Goodman furnace patented adaptive learning algorithm for maximizing igniter life The furnace is designed in a way that it suits multi-position installation- horizontal, vertical, left or right Multi-speed, energy saving PSC direct drive blower motor