compression and expansion in practice however there will still likely be a temperature rise or drop during flooded compression and expansion respectively in which case it can be advantageous to place additional heat exchangers 86 and 88 as shown in fig9 the additional heat exchangers 86 and 88 are in an arrangement similar to a brayton cycle cooler and serve to improve the performance of an ericsson cycle system whether for a heat pump e g fig1 or a heat engine e g fig3 fig1 represents a further modification of fig1 in which the heat exchangers 28 and 54 are relocated directly downstream of the compressor 12 and expander 44 respectively these locations allow for additional heat to be rejected q out and additional heat to be absorbed q in with the net effect that the coefficient of performance cop can be improved for the system 10 the improvement in cop is possibly such that the system of fig1 is believed to be a preferred configuration for a reverse ericsson cycle system of this invention in another embodiment shown in fig1 the liquid motor 24 and pump 42 are replaced with ejectors 90 and 92 respectively as known in the art ejectors use a high pressure fluid stream to compress a low pressure fluid stream to an intermediate pressure therefore in the embodiment of fig1 the ejector 90 is employed to reduce the pressure of the liquid stream 30 entering the compressor 12 and the ejector 92 is employed to increase the pressure of.