Central Air Conditioners and Heat Pumps


Central air conditioners and heat pumps use a vapor compression cycle to provide cooling or heating. The most common type of system, split systems, consists of an outdoor condensing unit and an indoor evaporator unit which are connected by a refrigerant line set or loop. As the refrigerant enters the indoor unit, its pressure drops causing it to evaporate and cool. A blower moves indoor air across the evaporator coil and then into a duct system for circulation through a building. Central air conditioners are most typically installed with a gas furnace. A heat pump is a central air conditioner that can be operated in reverse to heat indoor spaces during cold weather.


New standards for central air conditioners and heat pumps took effect in 2015. These standards, developed jointly by air conditioner manufacturers and efficiency proponents and adopted in a DOE regulation published in 2011, provide for the first-ever regional standards. The standards provide for a minimum cooling efficiency requirement of Seasonal Energy Efficiency Ratio (SEER) 14 for split system central air conditioners in the South and the Southwest. For the North, the standard remains SEER 13 (the level that took effect for the nation as a whole in 2006). In the Southwest (a region comprised of Arizona, California, Nevada and New Mexico), air conditioners must also meet an Energy Efficiency Ratio (EER) requirement which helps ensure efficient operation at high outdoor temperatures. For heat pumps, the standard is the same in all regions: SEER 14 and heating season performance factor (HSPF) of 8.2.

In 2015, DOE convened a negotiated rulemaking process to recommend the next revision to the central air conditioners and heat pump standards. The negotiation process succeeded and DOE published a direct final rule containing new standards in January 2017. The newly negotiated standard will take effect in 2023. As part of the negotiation process, the test method for air conditioners was updated and improved, which will cause an adjustment to air conditioners and heat pumps ratings, making the 2023 standard not directly comparable to the current standards. DOE estimates that the newly negotiated standards will save consumers about $12.2 billion from products sold over a thirty year period.


About 65% of existing U.S. homes have a central air conditioner and about 17% have a heat pump. However, with the exception of the coldest climates, virtually all new homes are built with a central air conditioner or heat pump. Compared to older units, products meeting the latest standards generally incorporate improved compressors, expansion valves and better and larger heat exchangers. Current standards can be met with single speed compressor technology, while advanced, variable speed products enable SEER performance far higher than the minimum standards and can also improve comfort by providing more even heating or cooling.

Projected Savings

Central air conditioner and heat pump standards (published in 2017)
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Energy saved (quads):
CO2 savings (million metric tons):
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Net present value savings ($billion) 7% discount rate:


Fact Sheets


ASAP Press Releases


Standards in the News


Federal Date States
Potential Effective Date of Updated Standard 2030
Updated DOE Standard Due 2025
4th Federal Standard Effective 2023
Potential Effective Date of Updated Standard 2022
4th Federal Standard Adopted (DOE) 2017
Updated DOE Standard Due 2017
3rd Federal Standard Effective 2015
3rd Federal Standard Adopted (DOE) 2011
Test Procedure - Last Revised - Active Mode 2008
2nd Federal Standard Effective 2006
2nd Federal Standard Adopted (DOE) 2001
1st Federal Standard Effective 1992
1st Federal Standard Adopted (Congress) 1987
NAECA Initial Federal Legislation Enacted 1987

Timeline reflects state standards from 2001 to present; federal standards from inception to present.