Advanced Daylight Admission Systems Using Auxetic Structures in Florida, USA

Abstract

Most thermal interactions between indoor and outdoor environments take place through building envelopes and particularly through windows due to glazing's inherently higher Uvalues. Therefore, an effective shading structure for windows, which simultaneously can provide sufficient illuminance levels, minimize excessive sun exposure, and ensure acceptable visual comfort by controlling the glare is highly desirable. Unlike static daylight control systems, dynamic daylight admission systems adjust the amount of intake sunlight with assistance from building occupants or mechanical devices. Studies to date have not thoroughly and comprehensively developed an alternative system in which a self-morphing structure that is responsive to changing outdoor environmental conditions in real-time can function as an adaptive daylight admission system. This paper has studied the effects of the adaptable auxetic shading structure with varying geometries to optimize illuminance levels, sun exposure, and reduce probability of glare. This study has developed a model to evaluate the illuminance and glare performance of the proposed shading system, and tested in the City of Gainesville, Florida, which is also applicable to other locations. The results suggest that the auxetic shading structure can effectively block sunlight from entering the space by adjusting its geometry in response to varying outdoor and sky conditions. In addition, a strong correlation can be found among daylight availability, sun exposure, and glare probability. Future studies may explore the effect of auxetic shading structures on energy consumption and thermal comfort parameters. In addition, the relation between auxetic shading devices and the health and wellbeing of building occupants may also be another factor to evaluate the effectiveness of this new generation of shading devices. Although this study focuses on the building-scale level of this shading system, future studies can investigate the urban-scale implementation of the proposed shading strategy.