The results of experimental investigations of a bundle of tubes of an evaporative tubular heat exchanger are presented in this article. Evaporative effectiveness and mass transfer coefficient are estimated over a wide range of operating conditions. Based on the experiments, correlations are derived using multiple regression analysis. Results show that as the cooling film flow rate increases, evaporative effectiveness and mass transfer coefficient increases provided that the air flow rate is constant which is flowing from underneath the tubes of the evaporative tubular heat exchanger. The tubes are subjected to simultaneous flows of cooling water from the top; air flows from underneath with controlled amount of relative humidity and the process fluid is flowing through the tubes. Developed correlations are helpful in improvement of the design of heat transfer devices and many other engineering applications. Consideration of Relative humidity as one operating variable leads to novelty in the present investigation.