Experimental study on an air-cooled air conditioning unit with spray evaporative cooling system

Improving the coefficient of performance (COP) of air conditioner with air-cooled condenser is a challenge especially in areas with hot weather. A spray evaporative cooling system is coupled with the air-cooled condenser of an air conditioning unit, and influence of different outdoor temperatures, mass flow rates of nozzles and operation modes of spray system on the performance of air conditioning system under are investigated. Experimental results show that the application of spray evaporative cooling system has significant effect on the performance improvement of the unit and the improvement rate rises as outdoor temperature increases. By using the spray evaporative cooling system in hot weather conditions, the power consumption can be reduced up by 22% and the COP can be improved by around 42.6%. Even if the spray energy consumption is taken into account, the values of COP are higher than the threshold value of the secondary energy efficiency (3.2). This study demonstrates that an air-cooled air conditioning unit coupled with spray cooling system is a kind of energy-efficient technique, which has a significant potential to improve the unit performance and reduce the electricity demand.