Multi-state vertical-blinds solar shading – performance assessment and recommended development directions

Abstract The aim of this paper is to evaluate the potential of a novel multi-state sun-tracking vertical-blind (ST-VB) concept using building performance simulation (BPS). A multi-domain simulation toolchain was developed and verified to evaluate the interior vertical-blind concept. The toolchain is used to quantify whole-building performance effects of design choices in the development of the initial concept within a larger framework of functional and aesthetic requirements. Multiple control concepts are tested, including different sun-tracking approaches, utilising the double-sided blind to switch between absorbing and reflecting solar radiation, and the ability to fully retract the blinds versus rotating them into an open position. Different possible materialisations of the blind are tested by evaluating the performance sensitivity of each of the potential control strategies to varying the blinds' solar and visible reflectance. The most promising ST-VB strategies perform substantially better than a conventional automated roller-blind strategy in terms of preventing visual discomfort (8% less DGPs 0.4exc0deg), the admission of daylight (75–99% higher sDA300lx/50% ), allowing for views to the outdoors (8–33% more hours with a view), and energy performance (11–35% reduction in primary energy consumption for heating, cooling and lighting). This research concludes with a set of recommendations for the development of the ST-VB system and by extrapolating the ‘lessons-learned’ for future research and development into multi-state solar shading systems. The novelty of this research can be found in that automated control concepts for interior vertical blinds have thus far been largely unexplored. Additionally, this research contributes to the body of knowledge on performance modelling of complex fenestration systems and the use of BPS in the, relatively new, context of product development.