A recently built experimental setup was employed for the estimation of the solid-liquid equilibria of alternative refrigerant systems. The behavior of two binaries, i.e., carbon dioxide + 1,1-tetrafluoroethane (CO2 + R134a) and nitrous oxide + 1,1-tetrafluoroethane (N2O + R134a), was measured down to temperatures of 142 K. The triple points of CO2 and N2O were measured to confirm the reliability of the apparatus. The triple point of R134a was also measured; however, the pressure at the triple point for this fluid was too low to be accurately measured with the current apparatus. All triple point data measured revealed a generally good consistency with the literature. The results obtained for the mixtures were interpreted by means of the Schroder equation.