Experiments were conducted to study the heat transfer characteristics of condensate on a vertical column of horizontal enhanced tubes. Three tubes arranged in a vertical column were set in stationary vapour. In the current experiment, six distinctly different enhanced tubes, including low-fin tubes of 26, 32, and 41 fins per inch (fpi) and three three-dimensional-fin tubes, were tested. In addition, a plain tube was also tested for comparison with Nusselt's theory. The working fluid used in the experiment is refrigerant R134a. Average condensing heat transfer coefficients were obtained from the modified plot technique.

KEYWORDS: condensation, refrigerants, R134a, tubes, experiment, heat flow, properties, testing, comparing, heat transfer coefficient, condensers, performance