The Federal Energy Management Program (FEMP) provides efficiency requirements and acquisition guidance for water-cooled ice machines. Federal laws and requirements mandate that agencies purchase FEMP-designated products or ENERGY STAR-qualified products in all product categories covered by these programs and in any acquisition actions that are not specifically exempted by law.

FEMP's efficiency requirements and acquisition guidance apply to ice making head and self-contained unit type water-cooled ice machines that generate cube ice at 60 grams (2 ounces) or lighter using the batch ice making process. Remote condensing units and ice machines that use the continuous ice making process (i.e., flake and nugget) are excluded. The ENERGY STAR Program covers air-cooled ice machines.

This acquisition guidance was updated in January 2020.

Meeting Energy Efficiency Requirements for Water-Cooled Ice Machines

Federal purchases must meet or exceed the minimum requirements shown in Table 1. These ice machines must be connected to a cooling tower; single-pass cooling using city water is not allowed. If access to a cooling tower is not available or if the cooling tower does not operate year round, then an ENERGY STAR-qualified air-cooled ice machine must be used.

Table 1. Efficiency Requirements for Water-Cooled Ice Machines
Machine Type

Harvest Rate
(lb/24 hours)

Maximum Energy Use
(kWh/100 lb of ice)

Maximum Potable Water Use
(gallons/100 lb of ice)

Self-Contained Unit50-1007.622
Self-Contained Unit101-1506.622
Self-Contained Unit151-2005.820
Self-Contained Unit> 2005.220
Ice Making Head50-3005.520
Ice Making Head301-4004.620
Ice Making Head401-5004.120
Ice Making Head501-7504.120
Ice Making Head751-1,4353.519
Ice Making Head> 1,4353.318


Energy use in Table 1 is measured in accordance with AHRI Standard 810 (I-P)-2012 with Addendum 1: Performance Rating of Automatic Commercial Ice Makers.

Make a Cost-Effective Purchase: Save $129 or More by Buying FEMP-Designated Products

FEMP has calculated that the required water-cooled ice machine model saves money if priced no more than $129 (in 2018 dollars) above the less efficient model; the best available model saves $272. These calculations are for a 250-lb/24-h self-contained-type water-cooled ice machine operating 250 days per year (typical for food service facilities preparing two meals per day). Table 2 compares a less-efficient model that just meets the current federal energy conservation standard for this product type, a model meeting FEMP efficiency requirements (required), and the best available model, and shows the lifetime cost savings of purchasing an efficient product.

The values in Table 2 are calculated using current federal guidelines (NISTIR 85-3273-34, March 2019), which shows that the FEMP Required model saves approximately 187 kWh and 1,012 gallons annually. This results in estimated lifetime savings of $129 over the Less Efficient model. In food service facilities that prepare three meals a day, seven days per week (e.g., military installations and Veterans Affairs medical centers) the savings will be greater.

Table 2. Lifetime Savings for Water-Cooled Ice Machines
PerformanceBest Available ModelRequired ModelLess Efficient
Annual Ice Production46,875 lb46,875 lb46,875 lb
Energy Use Rate4.8 kWh/100 lb5.2 kWh/100 lb5.6 kWh/100 lb
Annual Energy Use2,250 kWh2,438 kWh2,625 kWh
Annual Energy Cost$196$213$229
Potable Water Use17 gal/100 lb20 gal/100 lb22 gal/100 lb
Condenser Water Use3.96 gal/100 lb4.12 gal/100 lb4.28 gal/100 lb
Annual Water Use9,826 gal/100 lb11,307 gal/100 lb12,319 gal/100 lb
Annual Water Cost$47$54$59
Lifetime Energy Cost$1,479$1,622$1,751
Lifetime Operating Cost Savings$272$129===

View the Performance and Model Assumptions for Table 2

Performance Column

Annual Ice Production:  Shown in pounds per year, calculated at 250 lb/day multiplied by 250 days/year multiplied by a 75% duty cycle.

Energy Use Rate: Shown in kilowatt-hours per 100 lb of ice made (kWh/100 lb of ice).

Annual Energy Use: Assumes water-cooled ice machines operating 250 days per year, producing 250 lb of ice daily (46,875 lb annually).

Annual Energy Cost: Calculated based on an assumed electricity price of $0.09/kWh, which is the average electricity price at federal facilities.

Annual Water Use: Sum of potable water and condenser water use (in gallons per 100 lb ice) multiplied by annual ice production.

Lifetime Energy Cost: Future electricity and water price trends and a 3% discount rate are from Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis–2019: Annual Supplement to NIST Handbook 135  (NISTIR 85-3273-34).

Lifetime Operating Cost Savings: The difference between the lifetime utility cost (electricity plus water) of the less efficient model and the lifetime utility cost of the required model or best available model.

Best Available Model Column

Calculated based on the highest efficiency model identified in publicly provided manufacturer data as of December 2019; values shown are rounded to the nearest dollar. More efficient models may be introduced to the market after FEMP's acquisition guidance is posted.

Required Model Column

Calculated based on the current FEMP-designated efficiency requirements; values shown are rounded to the nearest dollar. Federal agencies must purchase products that meet or exceed these requirements.

Less Efficient Model Column

Based on products currently available on the market at time of analysis.

Determine When FEMP-Designated 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. FEMP considers up-front costs and lifetime energy savings when setting efficiency requirements. Federal purchasers can assume FEMP-designated products 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 FEMP's efficiency requirements (e.g., the best available model).

Claim an Exception to Federal Purchasing Requirements

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.

Incorporate Federal Acquisition Regulation Language in Contracts

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. 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.

Find Federal Supply Sources

The federal supply sources for energy-efficient products are the General Services Administration (GSA) and the Defense Logistics Agency (DLA). GSA sells products through its Multiple Awards Schedules program and online shopping network, GSA Advantage!. 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.

The United Nations Standard Products and Services Code (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. FEMP has developed a table of ENERGY STAR and FEMP-designated covered product categories and related UNSPSC numbers.

Water-Cooled Ice Machine Schedules and Product Codes

GSA offers ice machines through Schedule 51 V (Hardware Superstore) and Schedule 56 (Buildings and Building Materials/Industrial Services and Supplies).

The UNSPSC for ice cube makers is 24131901.

Buyer Tips: Make Informed Product Purchases

Water-cooled ice machines should only be used when they can be connected to a cooling tower that operates year-round. Federal agencies should not use single-pass or once-through cooling, a practice where potable water is used to remove waste heat from the condenser and then disposed of down the drain. Federal water efficiency best management practices advocate against this practice. FEMP's Best Management Practice for Single-Pass Cooling Equipment recommends that ice machines and other equipment using single-pass cooling be modified to recirculate water or be eliminated altogether. In situations where connecting to a cooling tower is not possible or the cooling tower does not operate year-round, install ENERGY STAR-qualified air-cooled ice machines instead.

The type of ice maker purchased has energy use implications. Ice making head-type water-cooled ice machines do not contain storage bins, but are generally designed to accommodate a variety of bin sizes. Federal buyers need to be aware that the additional energy use associated with the storage bins is not included in the reported energy consumption for these products. Because self-contained units have an ice-making mechanism and a storage bin integrated into the same cabinet or housing, the energy use associated with the storage is included in the reported energy use.

Due to their high electricity demand, ice machines should be operated during off-peak hours if possible. This operating method requires purchasing larger storage bins and installing a clock or timer to prevent the machine from making ice during peak hours (usually between 12:00 p.m. and 6:00 p.m.). This operating strategy reduces the demand charges, resulting in additional cost savings.

User Tips: Use Products More Efficiently

Proper maintenance of water-cooled ice machines is important, especially of solenoid valves that control the flow of water through the condensers. When these valves fail in the open position, water flows through the condensers regardless of if the machine is operating or not. This unnecessarily increases loads on cooling towers.

Hard water leaves mineral deposits or scale on the evaporator plate and other components of the ice-making mechanism. Commercial ice machines typically include a self-cleaning function that periodically rinses scale off these components. In most cases, the owner or service technician can adjust the frequency of the cleaning function to accommodate differences in water quality. It is common to find ice machines with self-cleaning set to maximum regardless of water quality; be sure to check and adjust the setting to match the water quality in your area.

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