The document describes experiments conducted to enhance the performance of a household refrigerator by adding TiO2 nanoparticles to the compressor oil. Three experiments were performed: 1) with PAG oil, 2) with SUNISO 3GS oil, and 3) with SUNISO 3GS oil mixed with 0.05% TiO2 nanoparticles. Results showed that actual COP increased by 21% with pure SUNISO 3GS oil and by 35% with the nano-lubricant oil mixture compared to PAG oil. Power consumption was also reduced by 17.25% with pure SUNISO 3GS oil and 25.83% with the nano-lubricant oil. The nano-lubricant improved heat transfer and reduced friction inside the