Over the past few years, significant technological progress has been observed in the vehicles heating and cooling systems. This development is related to electro mobility which is getting popular nowadays. Vehicles equipped with batteries are challenging for the constructors in terms of keeping an efficient source of heat and cooling without reducing the vehicle range. Current problems with the range of electric vehicles are caused by the limitations of used refrigerants and design of heating and cooling systems. It has been observed, that the most efficient solution is based on a heat pump system. The development of heat pump systems includes the indication of a boundary conditions that directly affect the vehicle's range. The aim of this work is to present the thermodynamic characteristics of the refrigerants for different heating and cooling systems in an electric car equipped with a heat pump. The study shows the effect of the specific temperatures adopted for the design of heating/cooling systems on the efficiency of the system. Based on the example of two configurations: (1) single-stage heating and cooling system with steam compression, (2)and system with internal heat exchanger, a calculation analysis of heating and cooling systems with R134a and R1234yf have been carried out. Differences in individual points of the operating cycle of R134a and R1234yf having direct influence on the car use have been indicated.