high efficiency furnace corn burning stove corn burning furnace HIGH EFFICIENCY FURNACE Heat from this high efficiency furnace is easily distributed in a house or shop using a variety of water to air heat exchangers. If there is an existing furnace with duct works in the house, simply install a heat exchanger into the ductwork. If there is no existing ductwork, in-floor heat can be used, installing baseboard radiators, or even installing a heat exchange unit to provide heat.