This page provides acquisition guidance for residential central air conditioners. Federal laws and requirements mandate that agencies purchase ENERGY STAR®-certified products or Federal Energy Management Program (FEMP)-designated products for all covered product categories except as specifically exempted by law.
FEMP's acquisition guidance and associated ENERGY STAR efficiency requirements for residential central air conditioners apply to single package, split systems, and gas/electric package unit models that operate on single-phase current and have cooling capacities less than 65,000 Btu/hour.
Room air conditioners (window and through the wall) are covered by separate ENERGY STAR product requirements and efficiency criteria. Central air conditioners that operate on three-phase current and packaged terminal units are excluded.
This acquisition guidance was updated in December 2024.
How To Find Product Efficiency Requirements
The U.S. Environmental Protection Agency (EPA) provides residential central air conditioner program requirements and efficiency criteria on the ENERGY STAR website. Manufacturers meeting these requirements are allowed to display the ENERGY STAR label on complying models. Federal buyers can use ENERGY STAR's list of certified residential central air conditioners to identify or verify complying models. Buyers can also find qualified products on the Consortium for Energy Efficiency/Air Conditioning, Heating and Refrigeration Institute (CEE-AHRI) Directory of Efficient Equipment database.
To reflect the influence of climate on heat pump use, EPA specifies efficiency levels for residential central air conditioners by region: Southeast, Southwest and Northern, which effectively includes all states outside of those with hot/dry or hot/humid climates.
How To Determine Cost Effectiveness
An efficient product is cost effective when the lifetime energy savings exceed the up-front cost premium (if any) compared to a less efficient option. You can find more information about determining life cycle cost effectiveness on our general guidance page.
Federal buyers may find the most relevant guidance in Tables 1-3 below based on the planned location of the installation. Each example compares the life cycle cost savings of a base model (less efficient than the ENERGY STAR required efficiency), a model meeting the ENERGY STAR efficiency and a model with the highest available efficiency.
Example 1: Hot-Humid/Southeast States
FEMP has calculated that the required ENERGY STAR-qualified residential central air conditioner saves money if priced no more than $1,853 (in 2023 dollars) above the less efficient model. The best available model saves up to $6,724 (or $4,871 above the required model).
Table 1. Lifetime Savings for Efficient Residential Central Air Conditioner Models in Hot-Humid/Southeast States1
| Performance | Best Available | ENERGY STAR | Less Efficient |
| SEER22 | 23.5 | 15.2 | 13.4 |
| Annual Energy Use | 5,222 kWh | 8,074 kWh | 9,159 kWh |
| Annual Energy Cost | $575 | $889 | $1,008 |
| Lifetime Energy Cost (18 years) | $8,922 | $13,793 | $15,646 |
| Lifetime Energy Cost Savings | $6,724 | $1,853 | ====== |
1 Hot-humid/Southeast states include: The states of Alabama, Arkansas, Delaware, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, Puerto Rico, South Carolina, Tennessee, Texas, Virginia, the District of Columbia, and the U.S. territories.
2 Effective Jan. 1, 2023, the U.S. Department of Energy changed the way HVAC systems are tested and updated the national standards for Heating Seasonal Performance Factor (HSPF) and Seasonal Energy Efficiency Ratio (SEER). With this change, new rating values and nomenclature are used to denote the efficiency ratings—HSPF2 (heating efficiency) and SEER2 (cooling efficiency). See definition in 10 Code of Federal Regulations (CFR) part 430, Subpart B, Appendix M and M1.
Energy Use and Cost Assumptions
Seasonal Energy Efficiency Ratio (SEER2): Shown in British thermal units per watt-hour (Btu/Wh).
Annual Energy Use: Based on the test method referenced in 10 CFR 430, Subpart B, Appendix M for a 36,000 Btu/h residential central air conditioner operating 3,409 per year as seen in the 2016 Technical Support Document: Energy Efficiency Program for Consumer Product: Residential Central Air Conditioners and Heat Pumps.
Annual Energy Cost: Calculated based on an assumed electricity price of 11¢/kWh, which is the average electricity price at federal facilities throughout the United States as of July 2024. Learn more about Federal Government Energy/Water Use and Emissions data.
Lifetime Energy Cost: The sum of the discounted values of annual energy cost with an average residential central air conditioner life of 18 years. Future electricity price trends and a 3% discount rate are from Annual Supplement to NIST Handbook 135, Energy Price Indices and Discount Factors for Life Cycle Cost Analysis – 2024 (NISTIR 85-3273-39).
Lifetime Energy Cost Savings: The difference between the lifetime energy cost of the identified models.
Model Efficiency Levels
Best Available: Based on the model with the highest efficiency in the ENERGY STAR qualified products list as of December 2024. More efficient models may have entered the market after FEMP's acquisition guidance was created.
ENERGY STAR: Calculated based on December 2024 ENERGY STAR efficiency levels; values shown are rounded to the nearest dollar. Federal agencies must purchase products that meet or exceed ENERGY STAR efficiency levels.
Less Efficient: Based on the model with the lowest efficiency from market data collected by ENERGY STAR. Note energy savings will vary depending on actual usage.
Example 2: Hot-Dry/Southwest States
FEMP has calculated that the required ENERGY STAR-qualified residential central air conditioner saves money if priced no more than $869 (in 2023 dollars) above the less efficient model. The best available model saves up to $3,154 (or $2,285 above the required model).
Table 2. Lifetime Savings for Efficient Residential Central Air Conditioner Models in Hot-Dry/Southwest States3
| Performance | Best Available | ENERGY STAR | Less Efficient |
| SEER24 | 23.5 | 15.2 | 13.4 |
| Annual Energy Use | 2,450 kWh | 3,787 kWh | 4,296 kWh |
| Annual Energy Cost | $270 | $417 | $473 |
| Lifetime Energy Cost (25 years) | $4,185 | $6,470 | $7,339 |
| Lifetime Energy Cost Savings | $3,154 | $869 | ====== |
3 Hot-dry/Southwest states include: The states of Arizona, California, Nevada, and New Mexico.
4 Effective Jan. 1, 2023, the U.S. Department of Energy changed the way HVAC systems are tested and updated the national standards for Heating Seasonal Performance Factor (HSPF) and Seasonal Energy Efficiency Ratio (SEER). With this change, new rating values and nomenclature are used to denote the efficiency ratings—HSPF2 (heating efficiency) and SEER2 (cooling efficiency). See definition in 10 Code of Federal Regulations (CFR) part 430, Subpart B, Appendix M and M1.
Energy User and Cost Assumptions
Seasonal Energy Efficiency Ratio (SEER2): Shown in British thermal units per watt-hour (Btu/Wh).
Annual Energy Use: Based on the test method referenced in 10 CFR 430, Subpart B, Appendix M for a 36,000 Btu/h residential central air conditioner operating 1,599 hours per year as seen in the 2016 Technical Support Document: Energy Efficiency Program for Consumer Product: Residential Central Air Conditioners and Heat Pumps.
Annual Energy Cost: Calculated based on an assumed electricity price of 11¢/kWh, which is the average electricity price at federal facilities throughout the United States as of July 2024. Learn more about Federal Government Energy/Water Use and Emissions data.
Lifetime Energy Cost: The sum of the discounted values of annual energy cost with an average residential central air conditioner life of 25 years. Future electricity price trends and a 3% discount rate are from Annual Supplement to NIST Handbook 135, Energy Price Indices and Discount Factors for Life Cycle Cost Analysis – 2024 (NISTIR 85-3273-39).
Lifetime Energy Cost Savings: The difference between the lifetime energy cost of the identified models.
Model Efficiency Levels
Best Available: Based on the model with the highest efficiency in the ENERGY STAR Qualified Products List as of December 2024. More efficient models may have entered the market after FEMP's acquisition guidance was created.
ENERGY STAR: Calculated based on December 2024 ENERGY STAR efficiency levels; values shown are rounded to the nearest dollar. Federal agencies must purchase products that meet or exceed ENERGY STAR efficiency levels.
Less Efficient: Based on the model with the lowest efficiency from market data collected by ENERGY STAR. Note energy savings will vary depending on actual usage.
Example 3: Northern States
FEMP has calculated that the required ENERGY STAR-qualified residential central air conditioner saves money if priced no more than $927 (in 2023 dollars) above the less efficient model. The best available model saves up to $3,363 (or $2,436 above the required model).
Table 3. Lifetime Savings for Efficient Residential Central Air Conditioner Models in Northern States5
| Performance | Best Available | ENERGY STAR | Less Efficient |
| SEER26 | 23.5 | 15.2 | 13.4 |
| Annual Energy Use | 2,612 kWh | 4,038 kWh | 4,581 kWh |
| Annual Energy Cost | $288 | $444 | $504 |
| Lifetime Energy Cost (24 years) | $4,462 | $6,899 | $7,825 |
| Lifetime Energy Cost Savings | $3,363 | $927 | ====== |
5 North includes: All states not included in the hot-humid and hot-dry states.
6 Effective Jan. 1, 2023, the U.S. Department of Energy changed the way HVAC systems are tested and updated the national standards for Heating Seasonal Performance Factor (HSPF) and Seasonal Energy Efficiency Ratio (SEER). With this change, new rating values and nomenclature are used to denote the efficiency ratings—HSPF2 (heating efficiency) and SEER2 (cooling efficiency). See definition in 10 Code of Federal Regulations (CFR) part 430, Subpart B, Appendix M and M1.
Energy Use and Cost Assumptions
Seasonal Energy Efficiency Ratio (SEER2): Shown in British thermal units per watt-hour (Btu/Wh).
Annual Energy Use: Based on the test method referenced in 10 CFR 430, Subpart B, Appendix M for a 36,000 Btu/h residential central air conditioner operating 1,705 hours per year as seen in the 2016 Technical Support Document: Energy Efficiency Program for Consumer Product: Residential Central Air Conditioners and Heat Pumps.
Annual Energy Cost: Calculated based on an assumed electricity price of 11¢/kWh, which is the average electricity price at federal facilities throughout the United States. Learn more about Federal Government Energy/Water Use and Emissions data.
Lifetime Energy Cost: The sum of the discounted values of annual energy cost with an average residential central air conditioner life of 24 years. Future electricity price trends and a 3% discount rate are from Annual Supplement to NIST Handbook 135, Energy Price Indices and Discount Factors for Life Cycle Cost Analysis – 2024 (NISTIR 85-3273-39).
Lifetime Energy Cost Savings: The difference between the lifetime energy cost of the less efficient model and the lifetime energy cost of the ENERGY STAR model or best available model.
Model Efficiency Levels
Best Available: Based on the model with the highest efficiency in the ENERGY STAR Qualified Products List as of December 2024. More efficient models may have entered the market after FEMP's acquisition guidance was created.
ENERGY STAR: Calculated based on December 2024 ENERGY STAR efficiency levels; values shown are rounded to the nearest dollar. Federal agencies must purchase products that meet or exceed ENERGY STAR efficiency levels.
Less Efficient: Based on the model with the lowest efficiency from market data collected by ENERGY STAR. Note energy savings will vary depending on actual usage.
Where To Buy Compliant Products
Buyers can make sure the product they purchase will be compliant by incorporating federal acquisition regulation language into contracts. Compliant products can also be found using federal supply sources and product codes. See our general guidance page for more details on buying compliant energy-using products.
Residential Central Air Conditioner Product Codes
The Defense Logistics Agency Environmental Attribute Code (ENAC) identifies items with energy characteristics that meet standards set by an approved third party, such as FEMP and ENERGY STAR. Purchasers can also use a United Nations Standard Products and Services Code (UNSPSC) to identify and buy products and to track purchases.
The Defense Logistics Agency (DLA) ENAC for residential central air conditioners is LP.
The UNSPSC for air conditioners, including residential central air conditioners, is 40101701.
Other Tips for Choosing and Using the Best Product Efficiently
Tips for Selecting and Installing the Best Central Air Conditioner
When comparing different types of residential central air conditioners it is important to consider the seasonal energy efficiency ratio or SEER, which is shown on the yellow EnergyGuide label required on these products. As shown in Table 1, ENERGY STAR-qualified products need less power to operate. Buyers can use this table as a guide when replacing standard residential central air conditioners with more efficient products.
Federal buyers should require that residential central air conditioners are installed in accordance with the ANSI/ACCA – 2015: HVAC Quality Installation Specification. Installation problems like oversizing, improper charging, and leaky ducts result in efficiency losses, occupant discomfort, and shortened equipment life. Requiring the contractor to follow the quality installation guidelines will assure that these and other problems are addressed and that the energy and cost savings are achieved.
Refrigerants with ozone destroying hydrochlorofluorocarbons (HCFCs) were commonly used in air conditioners. When retiring models that contain HCFCs, the Clean Air Act requires that certified technicians recover the refrigerant on-site and dispose of it in an environmentally friendly manner.
Some utilities offer rebates or other incentives for the purchase of ENERGY STAR-qualified products. Use the ENERGY STAR Rebate Finder to see if your local utility offers these incentives.
Tips for Using Central Air Conditioners More Efficiently
When installed, operated, and maintained properly, energy-efficient residential central air conditioners provide years of safe and effective service. Federal users should be aware of the following user tips.
Consider leaving air conditioners off during unoccupied hours or using a programmable thermostat to minimize unnecessary operation of the unit. Regular maintenance (e.g., charging refrigerant and replacing filters) is necessary to maintain peak performance.