This research presents the effects of copper(II) oxide (CuO) and copper/silver (Cu/Ag) alloy nanoparticle incorporation on compressor oil (POE) of a vapor compression refrigeration system using HFC-R134a as refrigerant. Coefficient of performance (COP) was considered as performance parameter and evaluated based on the heat release rate and the compressor work. Friction and wear analyses of the reciprocating mechanism were also conducted to observe tribological effects of the nanoadditives on COP of the system. Furthermore, suction-discharge parameters of the compressor were evaluated to conduct precise determination of nanolubricant effect. The morphology of both nanoadditives and worn surfaces was analyzed via scanning electron microscopy. Energy-dispersive X-ray analyses were conducted to observe the chemical composition of the worn surfaces and thermogravimetric analyses were carried to determine the thermal stability of the nano-additives. The surface roughness's of the specimens were also examined to analyze wear characteristics. According to analyses, the most suitable amount of 0.5 vol% of Cu/Ag alloy and CuO nanolubricants provided the COP increments of 20.88% and 14.55%, respectively, with comparison to that of the compressor oil without nanoadditives due to tribological enhancement of the nanoparticles in the lubricant. Furthermore, the average coefficient of friction for Cu/Ag alloy nanolubricant was 5.5% lower than that of CuO nanolubricant and 9.9% lower than that of the pure lubricant.