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Ask the Expert: AFUE (Annual Fuel Utilization Efficiency)

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Energy GuideWith the fall/winter season upon us, many homeowners in the Twin Cities are wondering if their furnaces will make it another year. Some of them, in fact, wait until the equipment breaks to buy a new one. 

What’s AFUE (Annual Fuel Utilization Efficiency)? The term AFUE was established in 1978; AFUE is a measurement of heating output to the energy consumed over a heating season.

Why should you care? An AFUE rating of 70 percent means that all but 30 percent of the fuel energy consumed, was converted to heat for the home. In other words, if you spend $100 heating your home, it means that $30 went up the chimney! Literally, you’re “burning money.”

Increasing Column ChartDoes AFUE mean peak efficiency? It does not. The AFUE rating is intended to express the average annual furnace efficiency (not peak efficiency), taking into account standby and startup/shutdown heat losses.

Does AFUE guarantee the efficiency of installation? No. There are factors that are not included in the AFUE calculations, like the heat losses through the duct and piping system, whether the system is the right size for the home, and temperature control issues. Unfortunately, more than half of new furnace systems in U.S. homes do not perform to their rated efficiency as a result of improper installation. In fact, improper installation can reduce performance by as much as 30%.

What are the regulations around AFUE? The U.S. Department of Energy has a set minimum AFUE standard for furnaces. The current minimum AFUE is 78 percent for a gas-forced air furnace. High-efficiency furnaces start at 90 percent AFUE.

Energy Star LogoSince 2006, Standard Heating has been partnering with the US Environmental Protection Agency (EPA) and the Department of Energy (DOE) in promoting products that use less energy while providing the same or better performance than conventional designs. Use of these ENERGY STAR heating and cooling equipment is an excellent way for us to help prevent pollution, protect the global environment, and help you save on energy bills. To learn more visit our ENERGY STAR page or call us today!

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