AFUE Ratings — What That Furnace Efficiency Number Is Really Telling You

November 26, 2013 - Published by Scott's Air

There was a time when the term “energy-efficient furnaces” would have elicited a chuckle. After all, in the 1970s, the only way a furnace could truly be “energy efficient” is if you didn’t run it at all.

Those days, thankfully, are gone.

Today, a furnace’s efficiency is measured by a benchmark known as annual fuel utilization efficiency or AFUE for short. This rating, measured as a percentage, tells you how efficiently a furnace can convert gas into heating energy. And the higher the percentage, the more heat a furnace can draw from each therm of gas. (Gas, by the way, is part of the equation because it is the most common source of heating fuel.)

Due in part to the efforts of the U.S. Department of Energy, furnaces have become more energy-efficient over the years. But the numbers tell the story: A gas furnace made in the early 1970s typically had an AFUE of about 65 percent. Today, the lowest efficiency allowed by law for new gas furnaces is 78 percent, and some models achieve 98 percent — clearly nothing to chuckle about.

What’s the catch, you might ask? In general, furnace prices generally increase in relation to their fuel efficiency. But this is less a “catch” than an investment in the future. You should begin to recoup the cost of an energy-efficient furnace right away through lower utility bills. In fact, the department estimates that consumers who purchase furnaces with high AFUE ratings can save up to 20 percent a year, right away.

To make your furnace purchase a bit easier, the Federal Trade Commission requires that new furnaces display their AFUE ratings. Still, there’s a lot more to selecting a new furnace than what meets the eye. And this includes sizing a furnace so that you select one that is neither too small nor too large for your home.

For assistance in making this important investment, call the furnace experts at Scott’s Heating & Air Conditioning. We’ll answer your questions and help you every step of the way – and we’ll help you start reducing your energy bills right away, too.

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Scott’s Heating & Air Conditioning is a full-service heating and air conditioning company and a Bryant® Factory Authorized Dealer in Central Florida. Whether you need repair, maintenance, or installation of a new heating or cooling system, we provide efficient, cost-effective, and professional service. When it’s hot, call Scott!