Spectrally selective design and energy-saving demonstration of a novel liquid-filled window in hot and humid region

Spectrally selective window provides a positive solution for the sustainable development of buildings in hot regions. In this study, a novel filuis-based spectrally selective design was proposed to achieve the light/heat decoupling of windows. In detail, the cooper ions and chlorophyll were blended in the aqueous solution to efficiently block the near-infrared (NIR) and ultraviolet (UV) energy, whilst maintaining a high visible transmittance. The blended solution was demonstrated to be highly advanced in solar light/heat decoupling, with a high light-to-solar heat gain (LSG) above 2.5. Meanwhile, the weathering assessment of the prepared solution indicates that it can maintain a fairly constant optical transmittance over a period of 8 months. With the light/heat decoupling solution, a triple-layered liquid-filled window (LFW) was conceptualized, and a model was then developed to calculate the window's annual energy-saving performance in a hot and humid city, i.e., Hong Kong. Results demonstrate that the LFW can ensure a feasible luminous that is higher than 40 % and low monthly average solar heat gain coefficient (SHGC) values ranging from 0.24 to 0.26 in all seasons. These features hold great promise for buildings located in hot regions, as they enable low-carbon operation.