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Keywords:Steady-state simulation、Semi-empirical model、Domestic refrigerators、Experimental validation 1. Introduction A household refrigerator is composed of a thermally insulated cabinet and a vapor-compression refrigeration loop as shown in Fig. 1. These refrigeration systems, on the whole, consume a large amount of energy since hundreds of millions are currently in use, and dozens of millions are coming onto the market every year. An understanding of the operational characteristics of a refrigeration system is vital for any energy optimization study, not only to predict its performance, but also to aid the decision making during the design process. The refrigerator performance is usually assessed by one of the following approaches: (i) simplified calculations based on component characteristics; (ii) component analyzes through commercial CFD packages; and (iii) standardized experiments. Although the first two techniques play important roles in component design,they do not provide enough information on component matching and system behavior, which is only obtained by testing the refrigerator in a controlled environment chamber. These tests, however, are time consuming and expensive. A faster and less costly alternative is the use of computer models to simulate the thermal- and fluid-dynamic behavior of refrigeration systems. Many mathematical models have been proposed in the past for refrigerator modeling. In one of the earliest studies, Davis and Scott [1] developed a mathematical model to predict the steady-state component behavior over a range of operating conditions, consisting of individual component sub-models that combined first-principles with a number of empirical parameters obtained from the literature. Simplistic models were used for heat exchangers as the evaporating and condensing pressures were assumed to be known. The compressor model, on the other hand, considered the in-cylinder compression and the pressure drops in the suction and disc