A comprehensive review of cover-shield-assisted radiant cooling system

As an alternative to all-air conditioning systems, radiant cooling has the potential for energy saving and better thermal comfort. One of the limitations of radiant cooling is the risk of condensation on radiating surfaces when the surface temperature falls below the ambient dew point temperature. One of the possibilities to avoid condensation is to isolate the cooling surface from the ambient air with a cover-shield, such as an infrared-transparent membrane or aerogel. This method would reduce surface convective cooling, making the system potentially applicable in outdoor and indoor spaces with natural ventilation. The objective of this review study is to provide a fundamental understanding of cover-shield-assisted radiant cooling systems. The present research study summarizes a review in terms of possible system configurations, the use of infrared-transparent cover materials, heat transfer modeling, ranges of cooling capacity, and thermal comfort performance. As cover-shield-assisted radiant cooling systems are in the early stage of development, this study would aid in identifying further research needs for engineering applications. Future research could focus on improving cover-shield strength and enhancing spectral IR transparency to further improve system design and performance. Additionally, the potential deployment of this technology in open spaces such as bus stops, sitting-out areas, and parks is yet to be explored.