In this study, heat transfer performance of nanofluids (Al₂O₃/water and CuO/water nanofluid) is experienced by using the condensing unit of an air conditioner. Nanoparticles at 30 nm are suspended at various volume concentrations (1%, 2%, 3%, and 4%) in the base fluid are produced for this current work. The nanofluids, considered as a cooling fluid, flow in the outer side of the tube of condenser, and general working condition of the air conditioner is applied for the investigation. Experimental results highlight the enhancement of heat transfer rate because of the existence of nanoparticles in the fluid. Two nanofluids show better heat transfer rate than does the base fluid. The Nusselt numbers for CuO/water and Al₂O₃/water nanofluids are enhanced up to 39.48% and 33.86%, respectively. The findings show that CuO/water nanofluids exhibit better heat transfer rate than Al₂O₃/water nanofluids.