The heat exchanger is an important component in the automobile, refrigeration, aviation, and oil and gas industry. In all the heat exchangers there is a heat transfer fluid. Generally, water, air, lubricating oil, and ethylene glycol are the most wildly used conventional heat transfer fluids. The thermal conductivity of these conventional heat transfer fluids is very low as compared to metal and metal oxides. Due to these reasons, there is a huge amount of energy loss, due to the scarcity of fossil fuels, which is a big issue. To circumvent this restriction. additives may be added to liquid coolants to enhance the particular characteristics of ordinary liquids. Adding high thermal conductivity particles to the liquid coolant may increase the heat transfer coefficient Nanoparticles are often added to heat transfer fluids to improve their thermal characteristics. In this study, an Alumina (AL2O3) based Nano fluid is considered as an additive. Using Computational Fluid Dynamic to study the performance enhancement of heat exchanger when mixing the aluminium Nano fluid to base fluid-Water. © 2023 Elsevier B.V., All rights reserved.