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For Homeowners

What Is AFUE (Annual Fuel Utilization Efficiency)?

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AFUE, or Annual Fuel Utilization Efficiency, is a measure used to assess the efficiency of gas-fired furnaces and boilers. It represents the percentage of heat produced from the fuel consumed over an entire heating season.

The concept of AFUE gained prominence in the 1970s as energy efficiency became a central concern. The U.S. Federal Trade Commission mandated AFUE ratings for heating systems to provide consumers with standardized information about equipment performance.
AFUE ratings help consumers understand how effectively a furnace or boiler converts fuel into heat. Higher AFUE ratings indicate greater efficiency, with modern high-efficiency gas furnaces typically achieving AFUE ratings of 90% or higher.

People Also Ask About AFUE:

What’s the difference between AFUE and thermal efficiency?

AFUE is specific to gas-fired heating systems and represents overall efficiency, including standby losses. Thermal efficiency refers to the combustion efficiency of a burner when it’s operating.

How can I improve my heating system’s AFUE?

Regular maintenance, proper insulation, and duct sealing can improve your heating system’s overall efficiency and contribute to a higher AFUE.

Is AFUE applicable to electric heating systems?

No, AFUE is specific to gas-fired heating systems that burn fossil fuels. Electric heating systems, like heat pumps, have their own efficiency metrics such as HSPF.

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