In this study, impacts of nanofluid use in thermoelectric coolers (TECs) on cooling power and main performance parameters are investigated through a comprehensive experimental methodology. For this purpose, a water cooled block is placed on the hot side of the Peltier and a water to air heat exchanger is integrated to the system in order to cool the heated water. Three different nanoparticles (Al2O3, TiO2 and SiO2) at a mass fraction of 0.1, 0.5 and 1% are added to the water running in the system and the temperature difference between the first and final state of the cooling process is determined for different ambient temperatures (18, 24 and 30 degrees C). As a second part of the research, 1 L of water is placed in the cooled cabinet, and the changes in temperature are observed under the same conditions representing the case of with load. The results indicate that the best enhancement in indoor temperature difference compared to water cooling is obtained for 1% Al2O3 at 30 degrees C ambient temperature with 26% for without load conditions. In addition, when the cooled water temperatures are taken into consideration, the best improvement is achieved as 55.1% from the 1% Al2O3-water nanofluid. Despite the small decreases in the coefficient of performance (COP) values of the system, it can be easily asserted that the novel TEC design integrated with nanofluids and water to air heat exchanger block is much more advantageous against the conventional water-cooled units due to the significant improvements in the cooled cabinet temperature.