when designing the refrigerant loop of a freezer, the heat exchangers and compressor are selected first. These components have clear trends; for example, the larger the area of a heat exchanger is, the lower the temperature lift that we can achieve. A compressor with higher efficiency is always welcomed, but for a capillary tube and refrigerant charge there is not such a clear trend as there is for heat exchangers or compressors. Thus, the capillary tube and the refrigerant exchangers and compressor are selected first. These components have clear trends; for example, the larger the area of a heat exchanger is, the lower the temperature lift that we can achieve. A compressor with higher efficiency is always welcomed, but for a capillary tube and refrigerant charge there is not such a clear trend as there is for heat exchangers
or compressors. Thus, the capillary tube and the refrigerant charge can be determined with an optimization process. Bj€ork and Palm (2006) and Boeng and Melo (2014) studied experimentally the energy consumption of a household refrigerator when the expansion capacity of the capillary tube and the refrigerant charge were varied. They presented energy consumption maps identifying the optimum region of expansion device capacity (EDC) and refrigerant charge in order to minimize the consumption. Bj€ork and Palm (2006) directly measured the energy consumption of the tested system during the cycling operation of the system, whereas Boeng and Melo (2014) estimated the energy consumption from the power consumption measured in steady-state tests (as proposed by Hermes et al., 2013).