This study investigates heat transfer enhancement in a horizontally oriented tubular heat exchanger using minijet impingement. The experiment involves a copper inner tube (14 mm internal diameter, 1 mm thickness) and an outer tube (29 mm external diameter, 1 mm thickness), with two perforated pipes (11 mm and 20 mm internal diameters) contributing to a total length of 281 mm. The cold water inlet temperature was maintained at 29 °C, while the hot water inlet temperatures varied between 55 °C, 75 °C, and 85 °C. The mass flow rate of cold water ranged from 0.01 kg/sec to 0.11 kg/sec, and the hot water flow rate remained constant at 0.11 kg/sec. The study aims to evaluate the impact of varying hot water inlet temperatures on heat transfer performance. The experimental setup includes a heat exchanger with a cold water stream directed to the heat exchanger and another to an electrical heater. Temperature measurements were taken using T-type thermocouples, and pressure drop was measured using a differential pressure transducer. The heat transfer coefficient and average heat transfer rate were calculated using the log mean temperature difference (LMTD) method. The results show that the average heat transfer rate increases with the cold water mass flow rate, and the heat transfer coefficient increases with the cold water flow rate. The study also demonstrates that the heat transfer rate is directly proportional to the cold water mass flow rate, as heat transfer across the test section depends on the heat capacity of the hot water. The findings indicate that the use of perforated tubes and varying hot water inlet temperatures significantly enhances heat transfer performance compared to a plain tube. The study concludes that innovative techniques such as jet impingement can effectively enhance heat transfer in tubular heat exchangers, leading to improved thermal efficiency in industrial applications.This study investigates heat transfer enhancement in a horizontally oriented tubular heat exchanger using minijet impingement. The experiment involves a copper inner tube (14 mm internal diameter, 1 mm thickness) and an outer tube (29 mm external diameter, 1 mm thickness), with two perforated pipes (11 mm and 20 mm internal diameters) contributing to a total length of 281 mm. The cold water inlet temperature was maintained at 29 °C, while the hot water inlet temperatures varied between 55 °C, 75 °C, and 85 °C. The mass flow rate of cold water ranged from 0.01 kg/sec to 0.11 kg/sec, and the hot water flow rate remained constant at 0.11 kg/sec. The study aims to evaluate the impact of varying hot water inlet temperatures on heat transfer performance. The experimental setup includes a heat exchanger with a cold water stream directed to the heat exchanger and another to an electrical heater. Temperature measurements were taken using T-type thermocouples, and pressure drop was measured using a differential pressure transducer. The heat transfer coefficient and average heat transfer rate were calculated using the log mean temperature difference (LMTD) method. The results show that the average heat transfer rate increases with the cold water mass flow rate, and the heat transfer coefficient increases with the cold water flow rate. The study also demonstrates that the heat transfer rate is directly proportional to the cold water mass flow rate, as heat transfer across the test section depends on the heat capacity of the hot water. The findings indicate that the use of perforated tubes and varying hot water inlet temperatures significantly enhances heat transfer performance compared to a plain tube. The study concludes that innovative techniques such as jet impingement can effectively enhance heat transfer in tubular heat exchangers, leading to improved thermal efficiency in industrial applications.