干旱区生态环境知识资源中心

Fully-glazed facades are increasingly common in contemporary buildings. They are further desired for hospital settings where greater connection to outside views is believed to contribute to patients’ health and wellbeing. In hot-arid climates, such a design attribute may contribute to excessive solar gain and consequent energy demand. Intelligent glazing technologies provide a potential solution for this with their capacity to autonomously change their optical/thermal properties in response to varying outdoor conditions. Although critical for regulating energy use, in conditions of excessive solar gain, the change of the window colour from clear to fully tinted might obstruct clear views to outside.

This study explores an approach to integrate intelligent glazing and shading devices in order to improve energy performance of fully-glazed buildings while allowing the window to remain more hours in a clearer state. To test this, seven intelligent glazing materials were identified and modelled interchangeably with a set of unobstructive shading devices. A typical hospital waiting area located in the outskirts of Cairo, Egypt with a southern orientation was investigated using EnergyPlus. Annual lighting and cooling loads were computed and compared to determine the combinations that yielded higher energy savings. The number of hours that each glazing spent in the different states was then calculated and compared. The integration of horizontal shadings contributed to additional energy savings while playing a role in improving visibility to outside by allowing the window to remain in a clearer state for an extended time without adversely impacting indoor visual comfort. Further research is warranted to explore alternate shading options, in addition to the implications of other climatic conditions, orientations and building types.