In this paper, an extensive experimental work has been carried out on phase-equilibrium measurements in binary systems constituted by refrigerants CF3-CHF2 (R125), CF3-CH2F (R134a), CF3-CH3 (R143a), and CH2F2 (R32) and a commercial perfluoropolyether Fomblin YLOX100 and Fluorolink D10H, used as lubricant oils. The measurements are related both to vapor-liquid and liquid-liquid equilibria, and the collected experimental data have been interpreted with the extended Flory-Huggins model. This model allows, simultaneously, good performances in the description of both the vapor-liquid isotherms and liquid-liquid miscibility gaps with the same set of adjustable parameters.