We measured vapor-liquid equilibria (VLE) for the pure, binary and ternary systems containing difluoromethane (HFC32), pentafluoroethane (HFC125) and 1,1,1,2-tetrafluoroethane (HFC134a). Fitting VLE data obtained to an extended BWR equation of state, binary interaction parameters were determined. Using the binary parameters, we could predict VLE for a ternary system at 333.15 K and 2.43 MPa in excellent agreement. In addition, estimation of coefficients of performance (COP) using the equation of state revealed about 15% energy-saving against HCFC22, when mole fractions of HFC32 and HFC125 are 0.485 and 0.250, respectively.