If you’ve encountered common specifications for home cooling and heating, you may have wondered, “What is AFUE?” Short for Annual Fuel Utilization Efficiency, it’s the metric that represents the efficiency of gas furnaces. Expressed as a percentage and typically included in the manufacturer’s data for new units, AFUE provides a simple, at-a-glance efficiency rating you can use when considering a replacement furnace.
What Is AFUE Standard Efficiency?
Gas furnaces today must meet a federally mandated minimum AFUE of at least 78%. By that standard, 78% of the natural gas combusted by the furnace produces heat for the house, while 22% of the gas is lost in the heating process, typically exhausted up the vent along with hot combustion gases. Gas furnaces with AFUE ratings up to 80% are considered standard efficiency units.
What Is AFUE High Efficiency?
An AFUE rating of 90% is considered high efficiency. While a standard 80% furnace utilizes a single heat exchanger, high-efficiency units incorporate a secondary heat exchanger that captures additional heat that’s normally ventilated in exhaust gases. Because more BTU units of heat are generated, these furnaces typically provide more home comfort at a lower monthly cost. Furnaces with AFUE ratings as high as 98.7% are now available.
Is AFUE All You Need to Know?
Beyond “What is AFUE?”, here are additional factors to consider if you’re trying to decide between a standard furnace and a high-efficiency unit:
- The initial purchase price of standard-efficiency furnaces is typically lower than high-efficiency models. On the other hand, monthly operating costs of an AFUE 80% model will be higher because it consumes more gas than a high-efficiency unit.
- Installation costs of a unit above 90% will be higher than those for a standard furnace, as high-efficiency models require vent alterations as well as condensate drainage not required by an 80% model.
For experienced professional answers to questions like, “What is AFUE?”, contact Paitson Bros. We’ve been keeping Terre Haute homes comfortable and efficient since 1922.
Jeff Paitson is a third generation business owner who continues to run the business with the same values that have been passed down from previous generations since 1922.
Jeff’s belief is that the business belongs to Jesus Christ; therefore 10 percent of the company’s profits go toward the Maryland Community Church.
Jeff is a Terre Haute Chamber of Commerce member and in his spare time, he enjoys 
Ethan Rayburn is a lifelong resident of Terre Haute and a 2005 graduate of Purdue University.
An Eagle Scout, Ethan spent four years as a non-profit executive with the Boy Scouts of America before joining Paitson Bros. as a comfort advisor and later General Manager. In that role, Ethan has brought a renewed enthusiasm for customer care, integrity, value, and service to Paitson Bros. Heating & Air Conditioning.
Ethan enjoys singing and was a member of the Purdue Varsity Glee Club. He also enjoys playing and coaching soccer, spending time with his family and two young boys, and volunteering his time and resources with his church, Terre Haute First Baptist Church, which he has attended from a very young age.
Paitson Bros
1 (812) 232-2347
Serving the Wabash Valley, IN Area Since 1922