3. Reciprocating refrigerant compressor

Let's compare the operation of a real compressor with that of the perfect isentropic compressor, and derive the definitions of the various efficiencies that characterize compressor operation. Let's base our reasoning on the operation of the reciprocating-piston compressor (the most widely used of all). The efficiencies we're about to define would also apply to other types of positive-displacement compressors (the machines that make up the vast majority of our techniques).