Chillers are used to cool water, and this water has the purpose to cool air, products, or equipment as required. Refrigeration contributes directly and indirectly to global warming. The direct impact occurs when the refrigerant is a greenhouse gas and escapes into the atmosphere. While the indirect impact is a consequence of the emission of greenhouse gas during the energy generation, which produce the electricity needed to power the equipment. The AHRI developed the Low GWP Alternative Refrigerant Evaluation Program, with the objective to minimize the direct contribution of refrigeration to global warming; Low GWP refrigerants were tested in the place of traditional refrigerants. This project studied R1234ze(E) as a substitute of R134a in the operation of a chiller. The results of the program developed by AHRI were used as a reference to compare the energy balance of the system and the design of the heat exchangers for each fluid. It was also studied if the local temperature influence in the choice between R134a and R1234ze(E) on the operation of the chiller. The simulation of the cooling system was done through the EES software. The results of the comparison between fluids was interesting, and R1234ze(E) was confirmed as a possible substitute for R134a, although some modifications in the equipment are required.