HFO and carbon dioxide cascade system with zero GWP.

The reason for the development of families of refrigerants up to the present HydrogenFluorineOlefins (HFOs) is discussed. The desirable features for refrigerants are outlined along with discussion of the need to compromise when choosing to use any particular refrigerant for a certain application. A way of using a specific HFO in combination with Carbon Dioxide (R744) is outlined and the outputs of a model of its use is given. This scheme is compared with a Carbon Dioxide alone system in a booster configuration.