The use of ejectors in the vapor compression refrigeration cycles as an expansion device is of great importance since they decrease the compression work and increase the evaporation capacity to make the overall cycle much more efficient. In this study, ejector expansion refrigeration cycle is compared with vapor compression refrigeration cycle as the starting point of the discussion. The environmentally friendly refrigerants, R1234yf and R1234ze(E) are chosen from the HFOs for the purpose of the performance improvement declarations and operation condition analyses regarding the ejector expansion refrigeration cycle, i.e., COP and entrainment ratio variations caused by the change in the area ratio. R134a as well is chosen from the HFCs in order to create a comparative basis although it is about to be prohibited by Directive 2006/40/EC and Regulation (EU) No 517/2014. Thermodynamic models are established using Matlab (R) via conservation laws of mass, momentum, and energy. (C) 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 4th International Conference on Energy and Environment Research.