Preliminary performance investigation of a novel direct contact evaporative cooling system

Buildings are responsible for about 47% of total energy consumption in the world. The energy consumed is mainly for cooling, heating and ventilation. It is noted that energy requirement for cooling reached 14.6% per annum between 1990 and 2000. Energy demand of buildings will continue to rise in near future owing to long-term use of buildings, increasing comfort demand of occupants and growth in population. In this regard, the aim of evaporative cooling systems is to mitigate the energy consumption and cost of operating a building by transferring heat between two fluids. An evaporative cooling system simply works as increasing the moisture contents of the air with use of water. When hot and dry air welcomes water, the water starts to evaporate with help of energy taken from the air. Thus the air becomes cooler whereas its relative humidity ratio goes up. The evaporative cooling system can be categorised as direct contact or indirect contact with respect to interaction between the streams. In this paper, domestic application of a novel direct contact evaporative cooling system is experimentally investigated. Within the concept of this research, performance evaluation of the system is introduced. For different temperatures of inlet fresh air, outlet temperatures are measured time-dependently and the level of cooling achieved is determined. Proper temperature and relative humidity measurements are performed for a reliable performance assessment. The results indicate that the efficiency of evaporative cooling is very promising. Even if extreme weather conditions are considered for air at the inlet, more than 20 °C temperature difference can be obtained with a remarkably high range of COP. In this respect, it can be easily concluded that the system provides very promising results for hot and arid climates.