The compression cycle in reciprocating compressors is a transient phenomenon that occurs in a time scale of about milliseconds and, for this reason, experimental measurements are not simple. Therefore, it is common to use CFD simulations to study the compression cycle, a procedure that has been continuously employed at POLO over the last 20 years. These simulations are usually conducted using commercially available software, and are focused on the compression chamber as well as on other compressor components, such as filters and gaps. POLO possesses the know-how of whole simulation process, from the geometry generation through the analysis of engineering results. Currently, two main activities regarding this subject are being conducted. The first is related to the simulation of the transient fluid flow and heat transfer inside the suction muffler, with focus on suction superheating. The second activity is a comparative analysis between two mesh models employed to simulate the compression cycle.  One is widely spread in the literature and (Moving Mesh – MM) while the other is a new type of mesh model (Automatic Mesh Refinement – AMR), which is intended to reduce the time spent to build and improve the mesh for engineering simulations. The objective of the project is to evaluate if the AMR model produces results as reliable as the ones given by the MM model, which is more established in the technical literature.