TL;DR
AFUE, annual fuel utilization efficiency, is the percentage of a furnace's or boiler's fuel that becomes usable heat over a typical heating season, with the rest lost up the flue. Federal minimums currently sit at 80 percent for most gas furnaces, while condensing models reach 90 to 98.5 percent by capturing heat from exhaust water vapor.
What it means
AFUE, annual fuel utilization efficiency, is the percentage of a furnace's or boiler's fuel that becomes usable heat over a typical heating season, with the rest lost up the flue. Federal minimums currently sit at 80 percent for most gas furnaces, while condensing models reach 90 to 98.5 percent by capturing heat from exhaust water vapor. The rating appears on the yellow EnergyGuide label and in every equipment proposal. Jumping from an old 70 percent unit to a 96 percent condensing furnace cuts gas use for heating by roughly a quarter.
Where it sits in the glossary
AFUE is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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