In the event that a high COP of a refrigeration cycle is of greater importance compared to other factors, it is possible to significantly increase the COP of a basic cycle through the use of a multistage vapor compression cycle. This is especially true when the pressure ratio between the heat rejection and heat absorption pressures is large 5 or more. Multistaging involves one or more intermediate pressures between the heat rejection and heat absorption pressures, and a series of compressors operating between successive pressure intervals. Cascade cycle is simply a chain of single stage vapor compression cycles operating in series, such that the condenser of a lower temperature cycle provides the heat input to the evaporator of the higher temperature cycle.