Heat and mass transfer for plate fin-and-tube heat exchangers, with and without hydrophilic coating

Heat and mass transfer characteristics of fin-and-tube heat exchangers with and without hydrophilic coating were reported in this study. The test exchangers consisted of three different louvre fin patterns and their corresponding plain fin counterpart. For completely dry test conditions. the enhancement level for the enhanced fin pattern decreases with increase of fin pitch. The Gray and Webb correlation considerably under-predicts the present 7.0 and 9.5 mm tube diameter plain fin samples. For dehumidifying test conditions, the effect of hydrophilic coating on the sensible heat transfer coefficients is negligible, and there are no detectable changes of the sensible heat transfer coefficients with change of inlet relative humidity. However, the pressure drops for the hydrophilic coated surfaces are sensitive to the inlet relative humidity. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.