It is certain that heat exchangers are a cornerstone in the modern industrial and technological scenery, as they mark their presence in a wide variety of applications. As a matter of fact, not only are they indispensable in day-to-day life and in domestic environments, but they also come across as crucial for energy efficient practices in the industry. Like so, the pump test facility in our university requires a heat exchanger which is needed for operations to be carried out properly at the pump lab. A detailed design of this heat exchanger is conducted based on specific operating conditions, in the goal of reaching the desired heat transfer and attaining a level of energy efficiency. Thereupon, a thermodynamic design method is explored, paired with a multiphase model simulated using the software OLGA. Finally, results of both tools are compared and matched to conclude optimum working conditions for the designed heat exchanger.