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What AFUE Means and How It Affects You

If you’re in the market for a new heating system or are taking a new interest in your current one, you’ll run across a slew of confusing acronyms. There’s one in particular you will see more than others: AFUE. On the cabinet of a gas-powered furnace you might read: “AFUE rating = 92%” What does this mean? Is it important to know?

We’ll explain AFUE in this post. To answer the second question first, yes, it’s important for you to know what AFUE stands for and what it means. This rating is key to understanding how energy-efficient a heater is and what you might expect to see on your heating bills.

For more information, as well as quality heating installation service in Beavercreek, OR, turn to Clean Air Act.

“Annual Fuel Utilization Efficiency”

AFUE is an acronym for “annual fuel utilization efficiency.” It’s a thermal efficiency rating that ranks how much heating power a heater returns from the fuel it uses, expressed as a percentage. (Air conditioners have a similar rating, SEER—seasonal energy efficiency rating—which is expressed as a ratio instead of a percentage.) It isn’t a “true” thermal efficiency rating, since it determines the heater’s efficiency over a long term instead of during steady-state, peak performance. It’s a number for consumers, not engineers.

An AFUE rating indicates the amount of heating power—measured in BTUs (British Thermal Units)—a heating system returns for every 100 BTUs of power it consumes. For example, if an oil boiler burned 100 units of oil and provided 80 units of heat, it would have an AFUE rating of 80%. The higher the percentage, the more completely the heater converts its fuel source into heat.

Why this is important

If you want to conserve energy and save money on your heating bill, a heater’s AFUE rating is one of the main aspects to consider.

Modern heaters score high AFUE ratings. The Department of Energy requires that all furnaces sold in the US must have an AFUE of at least 78%—and furnaces score higher than that. A top-of-the-line gas furnace can reach an AFUE rating of 96%. Boilers also are required to have high AFUE ratings, and most score above 85%. (Boilers in general are more efficient than furnaces.) To help you grasp these efficiency levels, consider that the AFUE of burning conventional firewood is a mere 45% to 55%.

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However, you shouldn’t simply pick the heating system with the highest AFUE rating. Aside from its increased cost, a heater with a high AFUE may not do the best job for your home, no matter its efficiency, if your house has less effective insulation or other specific requirements that make it harder to heat. This is why you should rely on professional advice and installation when it comes to heating your home. Contact Clean Air Act for assistance on making this important choice: AFUE is important, but it isn’t everything when it comes to heating in Beavercreek, OR.

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