This study examines the energy consumption of automatic ice makers installed in domestic refrigerators. The purpose of this research is to determine a method of measuring the energy consumption of automatic ice makers that will generate a repeatable and reproducible result. This study examined four refrigerator-freezers of different configurations, one top-mount unit, one side-by-side unit, and two French-door units with bottom freezers. The components and operational modes of each ice maker varied among the test subjects. This study examined each automatic ice maker and its components, and discussed how the operation of each component contributed to the overall energy consumption. Two of the units had a single-speed compressor that maintained the compartments within a range of temperatures by switching on and off. Since this type of unit draws considerable power when the compressor operates and very little when it doesn t, a good representation for energy consumption can only be characterized over a number of whole compressor cycles. However, the unit s ice maker also produces cyclic variation in power draw; therefore accurate measurement of the ice maker energy consumption must be characterized over a number whole of ice making cycles. Since the unit s compressor cycles and the ice making cycles are not coincident, it is difficult to determine the ice making energy using a predefined test period. The other two units employed inverter driven variable-speed compressors, which operated by maintaining a constant, part-load condition and did not cycle on and off. Determination of the ice making efficiency for these units was rather straightforward since data could be examined over a whole number of ice making cycles. We also examined the conditions which affect the ice making efficiency. The results showed that the ice making efficiency is influenced by the operating temperatures inside the cabinets."