Several models of Kerr furnaces in production as of 2015 qualify as Energy Star high-efficiency furnaces, according to the Department of Energy. These include models in the Paradigm, Compact, Summit and Eclipse furnace lines.
Kerr's Paradigm forced-air furnaces are the most efficient furnace models produced by the manufacturer. They have up to a 95 percent or better average fuel use efficiency, meaning that 95 percent of the energy in the fuel used in the furnace is converted to useful heat. This is achieved through the use of condensing technology that insures that more of the fuel is burned rather than being lost in exhaust gases. Combustion efficiency is also enhanced by use of a high-pressure combustion chamber to insure a more even and controlled burn. An additional benefit from the high combustion efficiency of the Paradigm furnace is that it produces cooler gases that can be vented into a plastic exhaust pipe directly through an exterior wall, so there is no need for a chimney for these furnaces.
Eclipse, Summit and Compact furnaces are somewhat less efficient than the Paradigm furnace line, with average fuel use efficiencies of between 86 and 87 percent. This is still efficient enough for Energy Star qualification, however.