The Federal Energy Management Program (FEMP) provides acquisition guidance for residential central air conditioners, a product category covered by ENERGY STAR.

FEMP's acquisition guidance and associated ENERGY STAR efficiency requirements for residential central air conditioners apply to single package and split system models that operate on single-phase current and have cooling capacities less than 65,000 Btu/h.

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 2022.

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. As of January 2021, the version 6.0 ENERGY STAR product specification for central air conditioners was not published. Please check ENERGY STAR's central air conditioners web page for updates on the version 6.0 specification.

Make a Cost-Effective Purchase: Save $394 or More by Buying ENERGY STAR

FEMP has calculated that the required ENERGY STAR-qualified residential central air conditioner saves money if priced no more than $394 (in 2021 dollars) above the less efficient model. The best available model saves up to $1,925. Table 1 compares three types of product purchases and calculates the lifetime cost savings of purchasing efficient models. Federal purchasers can assume products that meet ENERGY STAR efficiency requirements are life cycle cost-effective.

Table 1. Lifetime Savings for Efficient Residential Central Air Conditioner Models
Performance Best Available ENERGY STAR Less Efficient
SEER2a 28.0 15.0 13.4
Annual Energy Use 1,286 kWh 2,400 kWh 2,687 kWh
Annual Energy Cost $111 $207 $232
Lifetime Energy Cost (15 years) $1,766 $3,297 $3,691
Lifetime Cost Savings $1,925 $394 ======

a Effective Jan. 1, 2023, the 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 CFR part 430, Subpart B, Appendix M and M1.

Performance Column

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 operated 1,000 hours per year.

Annual Energy Cost: Calculated based on an assumed electricity price of 8.6¢/kWh, which is the average electricity price at federal facilities throughout the United States.

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 and NBS Special Publication 709, Energy Price Indices and Discount Factors for Life Cycle Cost Analysis – 2022 (NISTIR 85-3273-37 update 1).

Lifetime 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.

Best Available Model Column

Calculated based on the December 2022 List of Certified ENERGY STAR Products; values shown are rounded to the nearest dollar. More efficient models may be introduced to the market after FEMP's acquisition guidance is posted.

ENERGY STAR Model Column

Calculated based on December 2022 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 Model Column

Calculated based on typical products used in non-federal applications.

Determine When ENERGY STAR Products Are Cost-Effective

An efficient product is cost-effective when the lifetime energy savings (from avoided energy costs over the life of the product, discounted to present value) exceed the additional up-front cost (if any) compared to a less efficient option. ENERGY STAR considers up-front costs and lifetime energy savings when setting required efficiency levels. Federal purchasers can assume ENERGY STAR-qualified products and products that meet FEMP-designated efficiency requirements are life cycle cost-effective. In high-use applications or when energy rates are above the federal average, purchasers may save more if they specify products that exceed federal efficiency requirements (e.g., the best available model).

Contact ENERGY STAR for more information about annual and lifetime cost savings available from ENERGY STAR-certified products.

Purchasing Requirements

A gavel on top of a stack of papers.

Federal laws and requirements mandate that agencies purchase ENERGY STAR-qualified products or FEMP-designated products in all product categories covered by these programs and in any acquisition actions that are not specifically exempted by law.

These mandatory requirements apply to all forms of procurement, including construction guide and project specifications; renovation, repair, energy service, and operation and maintenance (O&M) contracts; lease agreements; acquisitions made using purchase cards; and solicitations for offers.

FAR Contract Language

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Federal Acquisition Regulation (FAR) Part 23.206 requires agencies to insert the clause at FAR section 52.223-15 into contracts and solicitations that deliver, acquire, furnish, or specify energy-consuming products for use in federal government facilities. 

To comply with FAR requirements, FEMP recommends that agencies incorporate efficiency requirements into technical specifications, the evaluation criteria of solicitations, and the evaluations of solicitation responses.

Products meeting ENERGY STAR or FEMP-designated efficiency requirements may not be life cycle cost-effective in certain low-use applications or in locations with very low rates for electricity or natural gas. However, for most applications, purchasers will find that energy-efficient products have the lowest life cycle cost.

Agencies may claim an exception to federal purchasing requirements through a written finding that no FEMP-designated or ENERGY STAR-qualified product is available to meet functional requirements, or that no such product is life cycle cost-effective for the specific application. Learn more about federal product purchasing requirements.

Federal Supply Sources and Product Codes

The federal supply sources for energy-efficient products are the General Services Administration (GSA) and the Defense Logistics Agency (DLA). 

The U.S. Department of Agriculture (USDA) and U.S. Environmental Protection Agency (EPA) provide programs that help federal agencies buy products with positive environmental attributes.

Identification codes for product categories covered by sustainable acquisition requirements are provided by DLA and the United Nations Standard Products and Services Code (UNSPSC).

Under the Multiple Award Schedule program, GSA issues long-term governmentwide contracts that provide access to commercial products, services, and solutions at pre-negotiated pricing.


DLA offers products through the Defense Supply Center Philadelphia and online through FedMall (formerly DOD EMALL).


Products sold through DLA are codified with a 13-digit National Stock Number (NSN) and, in some cases, a two-letter Environmental Attribute Code (ENAC). The ENAC identifies items that have positive environmental characteristics and meet standards set by an approved third party, such as FEMP and ENERGY STAR.

USDA's BioPreferred Program was created to increase the purchase and use of biobased products. Federal law, the FAR, and Presidential Executive Orders direct that all federal agencies and their contractors purchase biobased products in categories identified by USDA. 


EPA offers several resources for choosing which products to buy. The Environmentally Preferable Purchasing Program helps federal government purchasers utilize private sector standards and ecolabels to identify and procure environmentally preferable products and services.


UNSPSC is a worldwide classification system for e-commerce. It contains more than 50,000 commodities, including many used in the federal sector, each with a unique eight-digit, four-level identification code. Manufacturers and vendors are beginning to adopt the UNSPSC classification convention and electronic procurement systems are beginning to include UNSPSC tracking in their software packages. UNSPSCs can help the federal acquisition community identify product categories covered by sustainable acquisition requirements, track purchases of products within those categories, and report on progress toward meeting sustainable acquisition goals. 


Residential Central Air Conditioner Schedules and Product Codes

GSA offers central air conditioners through Multiple Award Schedule Industrial Products 333415HVAC, Hardware & Tools 332510S, and Hardware and Tools 332510C.

The DLA ENAC for residential central air conditioners is "LP."

The UNSPSC for air conditioners, including residential central air conditioners, is 40101701.

Buyer Tips: Make Informed Product Purchases

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 ENERGY STAR Quality Installation (QI) guidelines. 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 QI 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. FEMP's Energy Incentive Program helps federal agencies take advantage of these incentives by providing information about the funding-program opportunities available in each state.

User Tips: Use Products 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.


Lawrence Berkeley National Laboratory provided supporting analysis for this acquisition guidance.