Comparison of condensation heat transfer of three widely used refrigerants (R-22, R-134a, R-407C)

Heat transfer condensation tests for three widely used refrigerants (R-22, R-134a, R-407C) condensing inside a smooth tube are reported. The experimental runs to measure the heat transfer coefficients are carried out at an average saturation temperature of 40°C, at mass velocities ranging from 100 to 750 kg/(m2 s), over the entire vapour quality range. For R-134a condensation tests at 30, 50, and 60°C saturation temperature are also presented. In the case of R-407C, in-line concentration measurements are carried out by means of a gas chromatograph