(EP683810-A1)      A refrigerant medium consists of an azeotropic mixt. contg. (a) 50-95 wt.% fluorinated hydrocarbon and (b) 5-50 wt.% isobutane.    USE -   The refrigerant medium is used in refrigeration circuits as a replacement for chlorofluorocarbons.    ADVANTAGE -   Use of these media reduces risks of environmental pollution and depletion of the stratospheric ozone layer which may occur with prior art refrigeration media. The medium does not contain any environmentally noxious fluids that are likely to be banned as unacceptable. The mixts. are pure azeotropic fluids, evaporating constantly at 20C. In refrigeration appts. operating on a compression and expansion cycle, use of the claimed compsns. results in use of a smaller amt. of fluid and reduced energy use cf. conventional refrigerants. Performance capabilities are better than those obtd. with conventional refrigerant fluids.    (JP8506853-W)      A refrigerant medium consists of an azeotropic mixt. contg. (a) 50-95 wt.% fluorinated hydrocarbon and (b) 5-50 wt.% isobutane.    USE -   The refrigerant medium is used in refrigeration circuits as a replacement for chlorofluorocarbons.    ADVANTAGE -   Use of these media reduces risks of environmental pollution and depletion of the stratospheric ozone layer which may occur with prior art refrigeration media. The medium does not contain any environmentally noxious fluids that are likely to be banned as unacceptable. The mixts. are pure azeotropic fluids, evaporating constantly at 20C. In refrigeration appts. operating on a compression and expansion cycle, use of the claimed compsns. results in use of a smaller amt. of fluid and reduced energy use cf. conventional refrigerants. Performance capabilities are better than those obtd. with conventional refrigerant fluids.    (EP683810-B1)      A refrigerant medium consists of an azeotropic mixt. contg. (a) 50-95 wt.% fluorinated hydrocarbon and (b) 5-50 wt.% isobutane.    USE -   The refrigerant medium is used in refrigeration circuits as a replacement for chlorofluorocarbons.    ADVANTAGE -   Use of these media reduces risks of environmental pollution and depletion of the stratospheric ozone layer which may occur with prior art refrigeration media. The medium does not contain any environmentally noxious fluids that are likely to be banned as unacceptable. The mixts. are pure azeotropic fluids, evaporating constantly at 20C. In refrigeration appts. operating on a compression and expansion cycle, use of the claimed compsns. results in use of a smaller amt. of fluid and reduced energy use cf. conventional refrigerants. Performance capabilities are better than those obtd. with conventional refrigerant fluids.