Understanding What Furnace Efficiency Ratings Mean for Your Home’s Heating

Understanding What Furnace Efficiency Ratings Mean for Your Home's HeatingWhen you’re shopping around for a new furnace, efficiency is one of the first things you’ll want to get educated with. All furnaces are not of the same efficiency rating. To make comparison easier for consumers, furnace efficiency ratings are clearly listed on the equipment’s yellow EnergyGuide label. these ratings are listed for your information. Please read more…

Understanding AFUE

A furnace’s efficiency is indicated by its AFUE, or annual fuel utilization efficiency, number. This number represents what percentage of fuel used goes toward heating your home over the course of the heating season. For example, a high-efficiency gas furnace with an AFUE of 97 percent creates 97 Btus of heat with every 100 BTUs of gas it uses. The rest is typically lost to the outdoors and flue emissions. A higher AFUE means greater efficiency.

Minimum Efficiency Ratings

Knowing what minimum standards exist helps put furnace efficiency ratings into context. The U.S. Department of Energy (DOE) sets certain minimum efficiency standards for heating and cooling equipment manufacturers. Presently, residential gas furnaces must have a minimum AFUE of 80 percent.  Most recently, DOE tried unsuccessfully “push” the minimum rating to 90 percent AFUE. We can fully expect for this “push” to surface again as the federal government has put a temporary hold on its mandate.

A gas furnace with an AFUE of 90 or higher is considered a high-efficiency furnace, though furnaces today can reach efficiencies of up to 98.5 percent. To qualify for the Energy Star label, a furnace must have an AFUE of 90 percent or higher.

Choosing the Right Efficiency

Typically, the more efficient the furnace, the higher the purchase price. The return on your investment comes in the form of lower heating bills. Upgrading from a 60 percent AFUE furnace (early 1970s model) could cut your heating expenses by up to 40 percent. Depending on the efficiency of your old furnace, local fuel costs and how much you heat, you should recoup your investment in a high-efficiency furnace in around six or seven years.

The Timing Is Right

With natural gas prices relatively low as a result of increased domestic natural gas production, heating with a gas furnace is just about the cheapest way to go. This is true in many parts of the country, despite the fact that heat pumps are much more efficient at turning energy into heat. The low cost of natural gas can basically trump the efficiency advantage of a heat pump, though over time, that may not remain true, and isn’t the case now in some parts of the country.

For help understanding furnace efficiency ratings and finding the right equipment for your needs, contact us at Overland Park Heating and Cooling, serving the Greater Kansas City and Kansas area.

Our goal is to help educate our customers in Overland Park, Kansas about energy and home comfort issues (specific to HVAC systems). 

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