Investigation of separate or integrated provision of solar cooling and heating for use in typical low-rise residential building in subtropical Hong Kong

In this study, the technical effectiveness of solar cooling and heating was investigated for typical low-rise residential building in the subtropical Hong Kong. Since water heating was required for domestic hot water supply rather than space heating, a separate or an integrated provision of solar cooling and heating could be considered. In the separate provision, cooling was handled by an independent solar absorption air-conditioning system, while water heating was offered by a packaged solar thermal collector already equipped with a storage tank. In the integrated provision, all the solar collectors and a centralized hot water storage tank were collectively applied for both driving the absorption chiller and generating domestic hot water. Through year-round dynamic simulation, it was found that the integrated provision could have annual primary energy saving of 13.5% against the separate provision. The effectiveness of the integrated provision was further verified through two energy-saving scenarios, with energy reduction by 17.7% and 18.0% correspondingly as compared to the separate provision. Under the synergistic effect of centralized thermal harness and storage, the integrated solar cooling and heating is more appropriate for typical low-rise residential application in Hong Kong.