The U.S. Department of Energy (DOE) is a federal agency responsible for monitoring the consumption of energy sources and setting industry efficiency standards for all heating and cooling units manufactured in the U.S. Since as much as half of the energy used in your home goes to heating and cooling,* it helps to consider products with high efficiency ratings.

Ratings are different for each type of heating and cooling equipment, simply because of the energy source used to power it. For instance, the efficiency of electric cooling products is measured in SEER, with federal law mandating a minimum SEER of between 13 and 14. Currently, the Lennox^® SL28XCV is the most precise and efficient air conditioner you can buy,** offering up to an incredible 28 SEER.

The efficiency of heating equipment is measured in AFUE (for furnaces powered by fossil fuels like oil or natural gas) or HSPF (for heat pumps powered by electricity). And since heat pumps also provide home cooling in warmer months, they have both SEER and HSPF ratings. Lennox offers a variety of high-efficiency heat pumps and furnaces, including the SLP99V gas furnace — with an efficiency rating of up to 99%, it’s the quietest and most efficient furnace you can buy.† 

Learn more about efficiency standards governed by the Department of Energy

*Source: U.S. Department of Energy Statistics

**Efficiency claim based on comparison of the average SEER of the SL28XCV as compared to the average SEER of the competitive variable capacity compressor units as published in AHRI (December 2020). Actual system combination efficiency may vary; consult AHRI for exact system efficiencies. Precision claim based on the average cooling capacity range of the SL28XCV as compared to the average cooling capacity of the competitive variable capacity compressor units (December 2020). Averages calculated across 2, 3, 4 and 5 tonnage.

†Based on sound pressure levels during steady-state, high-fire and low-fire operation of Lennox^® SLP99UH070XV36B as of March 2020 at mid-point temperature rise and minimum external static pressure when set up per Section 4.4.4 of AHRI 260-2012. Based on AFUE efficiency rating of Lennox SLP99UH090XV60C and leading competitive units listed in AHRI directory as of December 2019. Efficiency ratings established per test standard ANSI/ASHRAE 103-1993.