Thermal behaviour of switchable liquid crystal glazing under real environmental conditions
摘要
Switchable liquid crystal glazing presents several advantages over conventional glass facades by seamlessly incorporating shading functions directly into the glass structure. This technology eliminates the need for mechanical components, enhancing reliability and reducing environmental impact. It also features rapid response times, within fractions of a second, and allows for variable shading levels, enabling precise adaptation to individual needs, thereby improving thermal and visual comfort. However, the design of these systems presents challenges, particularly with regard to the heating of the glass panes due to the absorption of solar radiation, especially when shading. Since the liquid crystals are embedded directly within the pane arrangement of the glazing unit, heat is transferred to the glass, causing uneven heat distribution, specifically in the clamped, shaded edge areas, which increases the risk of thermal stress fractures. Two types of glazing, double and triple, were installed and tested under real weather conditions in a facade test building to measure and assess the temperature behavior within the glass pane structure over a period of three years using various shading scenarios. The study revealed temperature extremes ranging from -9.9