The Federal Energy Management Program (FEMP) provides acquisition guidance for geothermal heat pumps, a product category covered by ENERGY STAR.

FEMP's acquisition guidance and associated ENERGY STAR efficiency requirements for geothermal heat pumps applies to open loop, closed loop, and direct geoexchange products that operate on single-phase current.

Commercial products (those that operate on three-phase electric current) are excluded.

This acquisition guidance was updated in December 2022.

Find Product Efficiency Requirements

The U.S. Environmental Protection Agency (EPA) provides geothermal heat pump 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 geothermal heat pumps to identify or verify complying models.

Make a Cost-Effective Purchase: Save $1,516 or More by Buying ENERGY STAR

FEMP has calculated that the required ENERGY STAR-qualified geothermal heat pump saves money if priced no more than $1,516 (in 2021 dollars) above the less efficient model. The best available model saves up to $5,124. 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 Geothermal Heat Pumps
Performance Best Available ENERGY STAR Less Efficient
EER/COP 30.5/5.2 17.1/3.6 15.0/3.1
Annual Energy Use-Heating and Cooling (kWh) 4,493 kWh 7,050 kWh 8,125 kWh
Annual Energy Cost-Heating and Cooling ($) $388 $609 $702
Lifetime Energy Cost (15 years) $6,339 $9,948 $11,464
Lifetime Cost Savings $5,124 $1,516 ======


Energy Efficiency Ratio (EER): Shown in British thermal units per watt-hour (Btu/Wh). 
Coefficient of performance: A unit less ratio of total heating energy output and the electrical energy input to the geothermal heat pump.

Annual Energy Use: Based on the test method referenced in ISO 13256-1:1998 "Water-source heat pumps — Testing and rating for performance" for a 36,000 Btu/h residential air-source heat pump operated 1,400 cooling mode hours and 1,400 heating mode 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 geothermal heat pump life of 25 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.


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.


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.


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.

Purchasing Requirements

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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. 


Buyer Tips: Make Informed Product Purchases

There are various types of geothermal heat pumps, including open loop, closed loop, direct geoexchange, and hybrid systems using several different heat sinks/sources. Learn more about the different types of geothermal heat pumps.

A proper assessment of the building's peak heating and cooling loads is critical to the design of a geothermal heat pump system. As with all heating and cooling equipment, oversizing of geothermal heat pumps, besides raising purchase cost, will result in decreased energy efficiency, poorer humidity control, and shorter product life, all due to excessive on-off cycling.

Accurate knowledge of the properties of the geothermal resource is also crucial in the design of a geothermal heat pump system. For ground-coupled systems, important parameters include the thermal conductivity and temperature stability of the soil formation. In larger installations, these properties are often measured directly in short-term tests at one or more locations on the site. Because ground heat exchangers represent a significant portion of the cost of these types of systems, it is important to size ground loops accurately. Software tools for ground loop sizing are available from a number of vendors.

The design of groundwater systems depends on several properties of the water source, including temperature, well flow rates, and water quality. Surface water systems, whether open or closed loop, depend on the temperature profile of the surface water body (through all seasons, as this may vary significantly).

Because geothermal heat pumps may be more costly to purchase than more conventional systems, direct procurement may be problematic. FEMP has a variety of project financing programs that allow federal facilities to leverage available resources with private financing to fund energy conservation measures, including geothermal heat pumps.

Many states and electric 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, geothermal heat pumps provide years of safe and effective service. Having a trained technician service the heat pump annually is necessary to maintain peak performance.


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