Abstract When humid atmospheric air is passed through a direct expansion or chilled water cooling coils, moisture is condensed if the coil surface temperature is lower than the dew point of air. For climatic conditions with high temperature and relative humidity such as those in UAE coastal regions, this cooling process, if optimized, can result in appreciable amounts of fresh water suitable for human consumption. In the present work, the cooling/dehumidification process is analyzed and the parameters controlling the heat and mass transfer rates are optimized for the climatic conditions in humid regions in the UAE.