Ventilation Benefits when Using Radiative Cooling Material in High Ambient Temperature Countries

Cooling in high ambient temperature (HAT) countries is a major energy consumer. In Kuwait, 70% of the electricity generated is consumed on cooling residential and commercial buildings. Because of the extreme temperatures in the summer, which can reach 50℃, outdoor fresh air vents are closed because AC units are incapable of cooling air at such elevated temperatures. Consequently, this has significantly reduced indoor air quality (IAQ) in residential and commercial buildings for indoor occupants. Recently, several researchers have shown that radiative cooling (RC) materials have huge potential in providing suitable daytime and nighttime pre-cooling for outdoor fresh air to indoor spaces. The objective of this study is to investigate the effect of radiative cooling materials on reducing the energy consumed on cooling in a typical house in a HAT country. This is done mainly by connecting a water pre-cooler heat exchanger to fresh air ducts to cool the outdoor ventilation air before entering the cooling coil. The water will be cooled via radiative cooling panels installed on the roof. A mathematical model of the hydronic RC panel is developed to predict the system operation and the RC power in Kuwait's climate that can be utilized in the pre-cooling of fresh air. Hence, the effect of installed RC panels on reducing the cooling load of a typical two-story Kuwaiti house is evaluated by integrating the RC system to the house thermal model to determine its energy performance with and without RC panels’ installation. The energy savings are estimated over the cooling season. It has been shown that substantial savings are achieved during night and day operations in the months of hot and dry weather.