An estimated one million automatic commercial ice makers in service in the United States consume about 8 billion kWh annually and cost American businesses more than $600 million in electricity [U.S. Environmental Protection Agency/Department of Energy. 2000. "ENERGY STAR.". Washington, D.C.: U.S. Environmental Protection Agency/Department of Energy]. Ice makers consist of two major energy-using subsystems: the refrigeration system and the water supply system. The greatest energy savings exist in the refrigeration system. Energy use for commercial ice makers can vary considerably from product to product depending on the machine's capacity, the type of ice produced (e.g., cubes, flakes, chips, nuggets, etc.), and the coolant used.

• Measuring Energy Use
• Choosing Energy-Efficient Products
• Energy Use and Cost Comparison
• New Products Coming to Market

A DOE study estimated that energy savings of 18 percent can be realized
through the use of high-efficiency compressors and fan motors, thicker insulation, and other measures, at an added cost that is expected to pay back in a little over two years [Arthur D. Little. 1996. Energy Savings Potential for Commercial Refrigeration Equipment. Cambridge, Mass.: Arthur D. Little].  

Measuring Energy Use

Ice machines that make cubes comprise more than 80 percent of ice maker sales. The Air Conditioning and Refrigeration Institute (ARI) developed a voluntary energy usage test standard for these machines. This standard measures ice harvest rate, energy use, and water use for several different types of ice-cube makers:

• Ice-making head units -- standard ice makers with the ice-making mechanism and the condensing unit in a single package, but with separate ice storage; 
• Self-contained units -- models in which the ice-making mechanism and storage compartment are in an integral cabinet; and
• Remote condensing units -- split-system models in which the ice-making mechanism, the condensing unit, and the ice storage bins are in separate sections.

These types of ice-cube makers are further subdivided into models that use air or water as their cooling medium. Approximately 80 percent of ice makers sold have integrated air-cooled condensers; the remaining have remote air-cooled or integral water-cooled configurations.  

All ice-cube machines that meet ARI standards are published in its Directory of Certified Automatic Commercial Ice-Cube Machines and Ice Storage Bins.

Choosing Energy-Efficient Products

Based on 1996 ARI data, FEMP developed an ice maker efficiency recommendation for federal purchasers. FEMP's levels represent products in roughly the top 25 percent of the market by energy performance. Their online buyer recommendation also includes an energy cost calculator to enable interested parties to compare the lifetime energy costs of different ice machines. Based largely on FEMP's recommendation, CEE developed a two-tiered energy efficiency criteria for ice makers. The CEE specification established efficiency levels as a straight-line function of the ice harvest rate, in contrast to FEMP's levels that are capacity specific, to minimize "gaming" by manufacturers. 

• Tier 1 is set at levels similar to FEMP's recommendation.
• Tier 2 is 20 percent more efficient than FEMP's recommendation, providing a target for manufacturer design efforts.

CEE also updates a list of qualifying products every six months.

Energy Use and Cost Comparison

Based on ARI data and manufacturer list prices (the latter from 1999), the table below shows that the most efficient ice maker models available use 18 to 34 percent less energy than the least efficient models, often at no additional cost.

Notes:

(a) The most efficient models on the market now may be more efficient than those identified here as the "best available," since more efficient models may have been introduced since the FEMP analysis.
(b) Assumes 50 percent discount from list price (based on communication with local distributors), 3,000 operating hours per year, and an electricity rate of $0.07/kWh.

Sources: ACEEE analysis based on data from ARI 1999. Directory of Certified Automatic Commercial Ice-Cube Machines and Ice Storage Bins. Air-Conditioning and Refrigeration Institute, Arlington, VA.; manufacturer catalogs.

New Products Coming to Market

Furthermore, more efficient designs are also possible. Manitowoc, for example, has announced the new series of models with energy savings up to 30 percent. It estimates the simple payback to the consumer at less than one year. It will introduce these models to the market in 2004.  Another major manufacturer has told us that it is now designing a new set of efficient models, targeting 20 percent energy savings relative to its current models.