Using Evaporative Cooling to enhance the thermal comfort conditions in Semi-open Areas.

Abstract

The rising global temperatures and increased frequency of heat waves have made it crucial to address the need for effective cooling solutions in semi-open spaces, such as outdoor cafes, large atriums with open ends, stadiums, prayer areas and public transportation waiting areas. The combination of the pedestal fan and mist water spray was introduced to explore the potential of utilizing evaporative cooling as a sustainable and cost-effective method for reducing ambient temperatures within such environments. The experimental study is conducted in a real semi-open environment and the data collection involved air velocity, air temperature, and relative humidity. Two different nozzle configurations were used to define the appropriate arrangement of nozzles and their number to maximize the cooling efficiency. The results showed that the axial air velocity during the mist condition decreased compared to that of the dry condition. The eight-nozzle configuration resulted in a greater reduction in air temperature over the four-nozzle configuration. However, an undesirable increase in humidity ratio resulted. A comparative analysis of the mist plate and mist nozzle revealed that the water particles of comparatively considerable size generated by the mist plate tended to fall within a limited distance without undergoing thorough complete evaporation, thereby failing to provide a sufficient reduction in air temperature. In all cases a distance of three meters from the fan is to be avoided to escape the uncomfortable wetting effect in this region.