Refrigerant compositions include mixtures of hexafluorodimethyl ether and cyclopropane, dimethylether or propylene; bis(difluoromethyl) ether and 2,2,3,4,4-pentafluorooxetane; fluoromethyl trifluoromethyl ether and 2,2,4,4,5,5-hexafluoro-1,3-dioxolane, 1-trifluoromethoxy-1,2,2,2-tetrafluoroethane, dimethylether or tris(trifluoromethyl)amine; trifluoromethyl methyl ether and perfluorooxetane, 2,2,4,4,5,5-hexafluoro-1,3-dioxolane, perfluoromethyl ethyl ether, perfluorodinethoxymethane, 1-trifluoromethoxy-1,2,2,2-tetrafluoroethane, dimethylether or tris(trifluoromethyl)amine; perfluoromethyl ethyl ether and dimethylether, propylene or 1-trifluoromethoxy-1,2,2,2-tetrafluoroethane; perfluorodirnethoxymethane and dimethylether or isobutane; 1-trifluoromethoxy-1,1,2,2-tetrafluoroethane and tris(trifluoromethyl)amine or dimethylether; difluoromethoxy pentafluoroethane and dimethylether, isobutane or tris(trifluoromethyl)amine; 1-trifluoromethoxy-1,2,2,2-tetrafluoroethane and dimethylether or isobutane; 1-difluoromethoxy-1,1,2,2-tetrafluoroethane and N(CHF.sub.2).sub.2 (CF.sub.3); or 1,1,1,2,2,3,3-heptafluoro-3-(1,2,2,2-tetrafluoroethoxy)propane and 1,1,2,2,3-pentafluoropropane or 1,1,1,2,3-pentafluoropropane.