“Furnace energy efficiency is measured in terms of Annual Fuel Utilization Efficiency or AFUE, which indicates the ratio of useful energy input to output as expressed in percentage. A modulating furnace, which increases and decreases heat gradually so the room temperature never varies more than 1 or 2 degrees from the target temperature, is a good example of an energy-efficient furnace.
Meanwhile, two-cycle gas heat furnaces do not short-cycle and are, thus, able to run on the lowest energy-saving levels. Finally, variable-speed motor furnaces are capable of relatively quiet operation due to the consistent motor speed. Local residents can count on a Madison, WI heating and air conditioning specialist such as Accu-Clime Mechanical Services, LLC to install furnaces with an 80% to 95% AFUE rating that can reduce heating costs without sacrificing comfort and warmth.”