The topic of improving the thermal performance efficiency of heat exchangers has received great attention from researchers due to their use in many industrial applications. Therefore, the improvement process has become important to increase the efficiency of the system and reduce the thermal load, thus reducing energy consumption and reducing the size of the exchanger. Researchers have used several methods to improve the performance of the heat exchanger. Some of them tried to increase the heat transfer surface area by used extended surfaces and some have worked to roughen the surface of the inner tube of the exchanger in different ways. All of this in order to increase the rate of heat transfer. By reviewing these researches, it was noted that adding extended surface, or made a dimples or cavities or roughness on the surface of the inner tube of the exchanger led to an enhancement in the heat exchanger performance.