Nocturnal Cooling-Assisted Hybrid Air Conditioning System

This paper reported a study on the desiccant dehumidification systems for hot and humid climate. In hot and humid climate conditions for maintaining the comfort conditions, using conventional air conditioner needs the Direct Expansion coil temperature below the dew point to condense water, the additional vapour which resulted relatively more consumption of electricity energy due to lower dew point and reheating. In response to these problems, solid desiccant cooling systems, which adopt nocturnal cooling and indirect-direct evaporative cooling have been recognized as a promising technology for their energy saving. Nocturnal cooling is an age-old technique to cool the structure based on the radiative cooling to the night sky and provides necessary cold water at 28-30°C for water cooling coil (WCC) unit. Results show that WCC brings down the process air temperature up to 22°C with the effectiveness of 90% and COP of hybrid system decreases as water flow rate decreases in WCC.