If you’re thinking of replacing your furnace and you live in Portland, then saving energy is likely at the top of your priority list. AFUE ratings are a way to assess the energy efficiency of furnaces and boilers. AFUE is an acronym for “annual fuel utilization efficiency.” It is calculated as a ratio that compares the heat output of the device to its fuel consumption. For example, if a furnace has an AFUE rating of 95%, this means that 95% of the fuel consumed heats the home, while the remainder is lost.
If you’re in the market for a new furnace that saves energy, you’ll want to choose a heating system that has an AFUE rating between 90% and 98.5%. These heating systems feature sealed combustion and a second heat exchanger that condenses flue gases. You might also consider talking to your HVAC technician about retrofitting your current furnace to save energy if you’re not quite ready for a replacement yet. In addition to making your furnace energy efficient, other options include installing a programmable thermostat and upgrading your ductwork.