AFUE

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(Annual Fuel Utilization Efficiency) is the standard measurement of efficiency for gas and oil-fired furnaces. Given in percentages, this number tells you how much of your fuel is used to heat your home and how much is simply wasted. The higher the AFUE rating, the greater the efficiency.

SEER

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(Seasonal Energy Efficiency Ratio) is the measure of efficiency by which the cooling process of air conditioners and heat pumps is rated. The higher the SEER number, the greater the efficiency, which translates into greater energy savings. Today, U.S. regulatory agencies require all new models to have a 10.0 SEER rating or better.

HSPF

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(Heating Seasonal Performance Factor) is the efficiency measurement used to gauge the efficiency of the heating mode of heat pumps. The higher the number, the greater the efficiency, which translates into greater energy savings. Today’s models are required to have a 6.8 HSPF or better.