The GMS80403AN 40,000 BTU up to 80% AFUE Performance Upflow gas furnace system from Goodman features several components that significantly enhance the efficiency and overall comfort of your home. The Goodman GMS80403AN furnaces feature the award winning, durable aluminized steel, reframed into a dual diameter configuration that vastly increases the reliability, durability and efficiency of the furnace. Not only this, this furnace incorporates a well insulated, heavy gauge steel cabinet that contributes in lowering the system operational sound levels to a negligible extent, providing comfortable and quiet heating for your home.