The inevitability of a disaster associated with the depletion of the ozone layer led to the decision to phase out conventional chlorine containing refrigerants and their mixtures. This necessitates the use of non-chlorine substances as refrigerants. In the present work, three different types of mixing rules, namely (i) the classical van der Waals one fluid mixing rule, (ii) the composition dependent mixing rules of the Margules type, and (iii) the conformal solution van der Waals mixing rules are used with the Peng-Robinson (PR) equation of state, to predict the VLE data of 27 alternative refrigerant mixtures, and the results are compared with the experimental data. It is found that the compositiondependent mixing rule coupled with the PR equation of state is quite suitable for predicting the VLE data.