Enthalpy and isothermal line near the point and dq_ cool=dP Tgc;out also can be obtained. In this study, REFPROP 8.0 (Lemmon et al., 2007) is used to calculate enthalpy and isothermal line. Dw_ =DP can be calculated with measured pressure values and power consumption. Finally, dq_=dw_ (Eq. (5)) is obtained dividing dq_ cool=dP Tgc;out by dq_ cool=dP Tgc;out . Using the above calculations, an electronic expansion valve was controlled to obtain desired heat rejection pressure.