The vapour-liquid equilibria (p, T. x) of a 1,1,1,2-tetrafluoroethane + ethylene-glycol dimethylether mixture was measured using the static method in the temperature range (283.15-353.15) K in steps of 10 K. The vapour-liquid equilibrium data were correlated by the temperature-dependent five-parameter non-random two-liquid (NRTL) equation. The data obtained in this experiment together with our previous experimental data for the binary system 1,1,1,2-tetrafluoroethane + triethylene-glycol dimethylether were used to calculate the UNIFAC interaction parameters for the CF3 and CH2F groups with the CH3, CH2, CH3O and CH2O groups. The resulting interaction parameters were used to predict the vapour pressures of the various mixtures studied in the literature. (C) 2008 Elsevier B.V. All rights reserved.