Plate & frame heat exchangers use a series of metal plates to conduct heat transfer between fluids. These fluids are directed through specific channels, ensuring they remain isolated while allowing efficient heat exchange. In recent years, researchers have looked at how different characteristics affect heat exchanger performance. The purpose of this study is to examine the impact of various factors on the effectiveness of the heat exchanger. The experimental analysis was conducted using pure water, considering different Re numbers ranging from 6000 to 30000 and varying hot fluid inlet temperatures between 25℃ and 35℃. It was observed that under turbulent flow conditions, the heat transfer effectiveness increased of 13.6% when the Reynolds number varied between Re = 6000 – 20000 at constant Th,in=35℃. However, the extent of this increase diminished significantly within the Re = 20000-30000 range. When the inlet temperature of hot fluid was raised Th,in=25℃ to 35℃ the plate & frame heat exchanger effectiveness increased of 4.3%. This study provides a basis for future studies on heat exchangers used in industrial applications with different geometries and different fluids. It is considered that the results of this study could be used in the future to design more modular and efficient plate heat exchangers for industrial applications.