1,1,1,2-tetrafluoropropene (HFO-1234yf) in automobile air conditioning methods are disclosed.

A refrigerant for a cooling device (10) comprising a cooling circuit (11) with at least one heat exchanger, in which the refrigerant undergoes a phase transition, the refrigerant being a refrigerant mixture composed of a mass fraction of carbon dioxide and a mass fraction of at least one other component, wherein the mass fraction of carbon dioxide in the refrigerant mixture is 10 to 50 mass percent, preferably 30 to 50 mass percent, the other component being pentafluoroethane and/or difluoromethane.

A refrigeration cycle apparatus (1) is capable of performing a refrigeration cycle using a small-GWP refrigerant. The refrigeration cycle apparatus (1) includes a refrigerant circuit (10) and a refrigerant enclosed in the refrigerant circuit (10). The refrigerant circuit includes a compressor (21), a condenser (23), a decompressing section (24), and an evaporator (31). The refrigerant contains at least 1,2-difluoroethylene.

According to the present invention, there is provided a composition carbon dioxide (CO.sub.2, R-744), difluoromethane (R-32) and 1,1-difluoroethylene (R-1132a).

A refrigeration cycle apparatus (1) is capable of performing a refrigeration cycle using a small-GWP refrigerant. The refrigeration cycle apparatus (1) includes a refrigerant circuit (10) and a refrigerant enclosed in the refrigerant circuit (10). The refrigerant circuit includes a compressor (21), a condenser (23), a decompressing section (24), and an evaporator (31). The refrigerant contains is a small-GWP refrigerant.

The invention provides a composition comprising (a) carbon dioxide (R-744, C0.sub.2); (b) difluoromethane (R-32); and (c)a third component selected from 1,1,1,2-tetrafluoroethane (R- 134a), trans- 1,3, 3, 3-tetrafluoropropene (R-1234ze(E)), 2,3,3,3-tetrafluoropropene (R-1234yf), 1,1,1,2,3,3,3-heptafluoropropane (R-227ea) and mixtures thereof.

The present invention relates to heat transfer compositions comprising 1-chloro-1,2 difluoroethylene for use in refrigeration, air conditioning, heat pump systems, chillers, and other heat transfer applications. The inventive heat transfer compositions can possess reduced global warming potential while providing good capacity and performance while providing preferable flammability characteristics

A cooling system includes a compressor configured to pressurize carbon dioxide to form pressurized carbon dioxide, a mixer configured to generate mixed refrigerant in which the pressurized carbon dioxide and solvent in a liquid state, a depressurization apparatus provided downstream from the mixer and configured to depressurize the mixed refrigerant, a separator configured to separate carbon dioxide in a gas state from the mixed refrigerant, a heat exchanger configured to exchange heat between the mixed refrigerant cooled through depressurization and a fluid to be cooled, and a second heat exchanger configured to cool the carbon dioxide or the mixed refrigerant using vaporized carbon dioxide or the mixed refrigerant.

A composition comprising: (i) 1,1-difluoroethene (vinylidene fluoride, R-1132a); (ii) carbon dioxide (CO.sub.2, R-744); (iii) pentafluoroethane (R-125); and (iv) one or more of trifluoromethane (R-23) and hexafluoroethane (R-116).

The invention provides a composition comprising carbon dioxide (CO2, R-744), difluoromethane (R-32) and trifluoroiodomethane (CF.sub.3I) and the use of such a composition as a working fluid in a heat transfer system, such as a refrigeration, heat pump or air-conditioning system.