For the refrigeration cycle shown in Figure 1 and Figure 2, the average saturated condensing temperature is assumed to be 65°F (18.3°C) and the average saturated evaporating temperature is assumed to be −20°F (−28.9°C). In addition, a superheat of 6°F (3.3°C) is assumed at the exit of the evaporator (location 3) and the return gas temperature at the compressor suction header is 30°F (−1.1°C) (location 4). The isentropic efficiency of the compressor is assumed to be 65%. Finally, no subcooling is considered in the condenser and no pressure drops are considered in the refrigerant piping. The thermodynamic states, including temperature, pressure, enthalpy, entropy and quality, around this hypothetical refrigeration cycle are shown in Table 1.