Ventilation increase using radiative cooling and phase change material at no additional energy cost in high ambient temperature countries

Abstract

In this work, a passive system composed of a radiative cooling (RC) panel combined with two phase change material (PCM) storage tanks was integrated with a conventional air conditioning (AC) system to minimize energy consumption of cooling the high temperature fresh air in the hot climate like Kuwait. The cooling power produced by the RC panel was used to charge the PCM storage tanks. One of these tanks was used for precooling the supplied fresh air (tank 1) and another for enhancing the coefficient of performance (COP) of the AC system by cooling the ambient air entering the condenser (tank 2). A mathematical model was developed for the proposed system and simulations were conducted for a typical Kuwaiti residence for the entire summer season extending from April to October. It was found that tank 1 resulted in an increase in the fresh air intake at zero energy expenses from 30 l/s/person to 190 l/s/person, with no required ventilation load from the AC system. Furthermore, tank 2 enhanced the COP by 10.5%. Thus, the overall energy consumption of the AC system was reduced by 22.3% with respect to the conventional AC system.