Utilization of auxetic structures in advanced shading systems to improve lighting and thermal performance in Florida, USA

Abstract

Due to inherently higher U-Values, heat transfer between indoors and outdoors mainly occurs through fenestrations. As a result, an effective shading structure that can provide sufficient illuminance levels while mitigating heat transfer through envelope, and also ensuring acceptable visual comfort by controlling the glare is highly desirable. Studies to date have not thoroughly developed a shading system where a computerized geometry, in a form of auxetic structure, can simultaneously provide sufficient daylight while avoiding glare and mitigating excessive heat transfer, which this study aims to address. This optimization was conducted through a mixed-method study, including simulation and experiment. The results showed that, on average, the auxetic shading structure reduced the illuminance level by over 50% minimizing the probability of glare, leading to potentially a better occupants’ visual comfort. The thermal analysis also showed that the auxetic shading system was able to reduce the indoor temperature between 5% - 8% around noon and afternoon. Additionally, the system reduced the indoor surface temperature for East, South, and West façades by 46.8%, 33.1%, and 32.3%, respectively. Such temperature reductions can potentially lead to improved thermal comfort for occupants.