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In this study, in a Vapor Compression Refrigeration System (VCRS) using R134a as refrigerant, R1234yf refrigerant considered as an alternative to R134a has been used as working fluid with the addition of aluminumdioxide (Al2O3) and Carbon NanoTubes (CNTs) nanoparticles. This system has been theoretically investigated in terms of thermodynamics under the same conditions, only by changing the working fluid. Investigations have been performed over a wide range for varying evaporation and condensation temperatures. The system using R134a and R1234yf as the working fluid have been analysed at the same conditions. As a result of the analyses at -7 °C evaporation and 45 °C condensation temperature, the Coefficient of Performance (COP) of the system has been calculated as 1.950 and 1.824 for pure R134a and R1234yf, respectively. There is a difference of 6.46% between COP values. Similarly, a difference of 6.44% between the second law efficiencies (exergy efficiencies) have been found as well. Thus, R1234yf refrigerant with the addition of Al2O3 and CNTs nanoparticles has been used as the nanorefrigerant instead of R134a refrigerant at the same conditions in analyses. As a result of the analyses, it has been observed that the COP and exergy efficiency increase with the nanoparticle volumetric concentration. Results have revealed that COP and exergy efficiency have increased up to values of 18.46% and 18.43% compared to usage of pure R134a refrigerant at -7 °C evaporation and 45 °C condensation temperatures for the R1234yf/Al2O3 nanorefrigerant, respectively. Similarly, these increases have reached up to values 6.92% and 6.89% for R1234yf/CNTs nanorefrigerant as well. [ABSTRACT FROM AUTHOR]