<p>This paper presents an experimental investigation on enhancing energy efficiency and cooling performance in a domestic vapor compression refrigeration (VCR) system using Al₂O₃–ZrO₂/PAG hybrid nanolubricants. The incorporation of nanoparticles into lubricating oils has been widely reported to enhance thermophysical properties, reduce energy consumption, and improve system performance. In this study, Al₂O₃ and ZrO₂ nanoparticles at concentrations of 0.2, 0.4, and 0.6&#xa0;g&#xa0;L⁻¹ were dispersed in Polyalkylene Glycol (PAG) oil using ultrasonication and magnetic stirring to produce well-dispersed under experimental conditions. The modified refrigeration system, charged with environmentally friendly R-600a (isobutane) refrigerant, was evaluated under steady-state conditions with respect to compressor power consumption, refrigeration capacity, and coefficient of performance (COP). The results show that hybrid nanolubricants increased cooling capacity by 5.9%, reduced compressor power consumption by 28.4%, and enhanced COP from 3.00 to 4.05, representing a 46.2% improvement compared to the baseline system. These findings show that Al₂O₃–ZrO₂/PAG hybrid nanolubricants significantly improve cooling performance and energy efficiency, indicating potential for eco-friendly domestic refrigeration applications. Furthermore, this study addresses existing gaps in stability, thermophysical enhancement, and long-term system reliability.</p> Graphical Abstract <p></p>