Hybrid solar water heating/nocturnal radiation cooling system I: A review of the progress, prospects and challenges

The need for substantial savings in building energy demand is necessitating global households' switch to solar water heating and nocturnal water cooling for possible incorporation with a hydronic system for controlling the temperature of buildings. Ambient energy technology application plays a prominent role in meeting the heating and cooling energy demands for buildings. These are not only environmental friendly but also require minimal maintenance and operation costs. A review of hybrid solar water heating/nocturnal radiation cooling system using a single collector/radiator for both functions is presented. The collectors that have been used for solar heating and cooling in meeting the building energy demand can be classified as photovoltaic-thermal collectors, water/air solar collectors and spectrally selective surface solar collectors. The performances of these collectors consistent with their usage at different regions of the world are concisely reported. The development of the primary component of the system, namely, the collector/radiator, vis-a-vis the combined heating and cooling function is examined. Current state of global system take ups are reported with factors limiting the widespread implementation. The prospects, technical advancements as well as technical, economic and societal constraints limiting the commercialization of the system are also reported, with suggestions for possible improvements. (C) 2019 Elsevier B.V. All rights reserved.