What is AFUE?
AFUE, or Annual Fuel Utilization Efficiency, is a metric used to measure the energy efficiency of heating systems, specifically furnaces and boilers. It represents the percentage of fuel that is actually converted into usable heat versus what is lost during the combustion process.
For example, a furnace with an AFUE rating of 90% means that 90% of the fuel is converted into heat, while the remaining 10% is lost through exhaust gases or other inefficiencies. The higher the AFUE rating, the more efficient the heating system.
AFUE ratings are crucial when selecting a heating system for residential and commercial buildings, as they directly impact energy costs and environmental efficiency. Older furnaces typically have AFUE ratings of 60-70%, whereas modern high-efficiency furnaces can achieve 95% or higher.
The U.S. Department of Energy sets minimum AFUE standards, requiring most new furnaces to have at least 80% AFUE, while high-efficiency models qualify for rebates and energy-saving incentives.
