The two-phase heat transfer coefficient and pressure drop characteristics of refrigerants R-22 and R-410A (a binary mixture of 50% R-32 and 50% R-125) for a smooth tube with a 6.54 mm ID are presented in this study. The data were taken at an evaporation temperature of 2°C. The mass flux was between 100 kg/m·s, the heat transfer coefficients for R-22, depending on the prescribed heat flux, may be higher than those of R-410A at a certain vapor quality. The pressure drop of R-410A is about 30%~40% lower than that of R-22.

Units: SI