Positive displacement compressors increase the refrigerant pressure by reducing the volume in which the fluid is trapped, also promoting the motion of the fluid through the refrigeration system. In refrigeration and heat pump applications, the compression technologies that stand forward are the reciprocating, rolling piston and scroll.

The reciprocating compressor dominates the domestic and light commercial refrigeration markets. For low capacity air conditioners, the rolling piston takes place due to its low cost, whereas for medium capacity the scroll compressor is usually employed due to its high reliability and efficiency. However, since the compressor technologies are evolving, there is a trend to the superposition in the range of capacities. For this reason, a careful comparative analysis is essential to evaluate the advantages and drawbacks of each technology at each of the operating conditions to which they will be submitted to.

As a result of the studies performed in the last 30 years, POLO acquired the necessary know-how and equipment to experimentally evaluate the reciprocating, rolling piston and scroll compressors. Additionally, numerical models were developed and validated to simulate each one of the aforementioned technologies.

Nowadays, the activities that are being developed aim the comparison of the different technologies for both air conditioning and heating applications. For air conditioning the technologies compared are the rolling piston and scroll compressors, focusing on the thermodynamic losses of each technology. Similarly, for the heating applications, the reciprocating and rolling piston are being studied but the analysis in this field is more extensive, including the electrical and mechanical losses. At the end of these activities, it will be possible to identify the most relevant design features in order to obtain the best performance of each one of the technologies.