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Furnace Efficiency Ratings

Understanding The Meaning Of The Furnace Efficiency Ratings For Your Home’s Heating.

When shopping around for a new furnace, efficiency is one of the first things you’ll want to get educated with. Unfortunately, all furnaces are not of the same efficiency rating. Furnace efficiency ratings are listed on the equipment’s yellow EnergyGuide label to make comparison easier for consumers. The EnergyGuide label lists these ratings for your information.

Understanding AFUE

A furnace’s efficiency is distinguished by its AFUE or annual fuel utilization efficiency. This number represents the percentage of fuel used toward heating your home over the totality of the heating months. For example, an efficient gas furnace with an AFUE of 97 percent will create 97 BTUs of heat to every 100 BTUs of gas it uses. The rest is generally lost to the outdoors and flue emissions. Furthermore, a higher AFUE means greater furnace efficiency.

Minimum Efficiency Ratings

Knowing what the minimum standards are helps put furnace efficiency ratings into perspective. The U.S. Department of Energy sets minimum efficiency standards for heating and cooling manufacturers. Nowadays, residential gas furnaces must have a minimum AFUE of 80 percent. Most recently, DOE tried unsuccessfully to “push” the minimum rating to 90 percent AFUE. In the future, we can expect this “push” to present itself again as the federal government has put a temporary hold on its ruling.

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

Choosing the Right Efficiency

Generally, the more efficient the furnace, the higher the purchase price. However, the return on your investment comes from lower heating bills. For example, upgrading from a 60 percent AFUE furnace (early 1970s model) could cut your heating expenses by 40 percent. Depending on local fuel costs and how often you use the heat, you should assume to recoup your initial investment in a high-efficiency furnace in about six or seven years. 

The Timing Is Right

With natural gas prices relatively low due to increased domestic natural gas production, heating with a gas furnace is more or less the cheapest way to go. This is true in most parts of the country, even though heat pumps are much more efficient at turning energy into heat. However, the low cost of natural gas can trump the efficiency advantage of a heat pump. Nevertheless, that may not remain true over time and isn’t the case now in some parts of the country.

Contact us at Paulson AC to help understand furnace efficiency ratings and find the right equipment for your needs.

At Paulson Air Conditioning, one of our primary goals is to help educate our customers in San Diego, California about energy and home comfort issues (specific to HVAC systems). Contact Paulson Air Conditioning today at (619) 305-1110 for a free estimate and receive 10% off new installation or service repair.