Development of an adaptive shading system based on analysis of study cases

Abstract

Over the last years, solar shading systems have become integral parts of the building envelope. New designs, technologies and materials are constantly introduced and tested in shading industry. Nowadays, adaptation in solar shading systems is the almost exclusive goal of every design. Adaptive solar shading systems are preferable as they adapt to external climate conditions and indoor needs, succeeding high performance and efficiency at the same time. The term “adaptation” is eventually related to movement. The plurality of adaptive solar shading systems perform by making use of integrated movement mechanisms. Ten Bucky-lab projects and ten study cases are analyzed in terms of visual comfort and analytical daylight simulations are conducted for the latter. The computer-based simulations focus on the annual daylight performance of each system in Athens. This procedure contributes in understanding in depth the way that adaptive shading systems perform, by evaluating their efficiency performance. This research highlighted the most efficient systems, under basic shading principles. However, their movement mechanisms are relatively expensive and require frequent maintenance or even replacement. The proposed solar shading system introduces a new generation of adaptive shading systems which are static and their adaptation mechanism is related to the material of the system and its properties. Smart glass technology and PDLC (Polymer Dispersed Liquid Crystal) devices allow the fluctuation of the transparency coefficient of the glass. They are mainly used as vertical glazing on the building envelope in order to provide shade to the interior. Nevertheless, being vertical, they do not only block daylight but also view to the exterior space. The proposed solar shading system makes use of this innovative technology in a more efficient way. An external three-dimensional grid, with vertical and horizontal components perpendicular to the facade of the building is placed in front of the curtain wall system, shading the interior and allowing view to outside simultaneously. Computer-based simulations are performed in detail for west and south orientations. A reference room on the 10th floor of an office building located in Athens is concerned. In addition, the proposed system is evaluated for the same reference room but located in Amsterdam via basic daylight simulations. The concept of this shading system is to provide the opportunity to control the transparency in great variety. Each component of the system can be controlled individually. Thus, either all or particularly selected horizontal and/or vertical shading components may be transparent or translucent. If shading is not needed, it may be totally invisible. As a result, the proposed shading system performs efficiently at any orientation and under any daylight conditions. Regarding efficiency performance, the proposed shading system provides acceptable indoor daylight conditions throughout the year in both examined orientations. The system requirements set for this research (daylit area, daylight autonomy, useful daylight index and glare percentage) are fulfilled. Focusing on its contribution in the energy consumption of the reference room, 35% energy saving is accomplished in south orientation and 16% in west orientation. These outcomes concern only the location of Athens