Gas Furnace AFUE Definition | HVAC Terminology
Gas Furnace AFUE Definition | HVAC Terminology. AFUE or Annual Fuel Utilization Efficiency Heating systems consume approximately 35% to 50% of a typical home’s energy budget. Therefore the government has come up with a way to measure efficiency ratings of furnaces so they can set a standard for minimum efficiencies.
The definition of AFUE is – Annual Fuel Utilization Efficiency. AFUE is a rating that reflects how efficiently a gas furnace converts fuel to energy. A gas furnace with an AFUE of 95 means that approximately 95 percent of the fuel is utilized to provide warmth to your home, while the remaining 10 percent flows up the flue and into the atmosphere.
Therefore you are actually using 95% of the fuel you are paying for and the other 5% is being wasted up the flue vent.
