Affective window: a seamless interaction between switchable glazing and the occupant

Abstract

New building technologies are developing rapidly, the use of sensors and actuation with it. These technological developments provide opportunities for buildings to react to their environment in real time. Hence, reducing the energy demand of the built environment which is critical in addressing the issue of climate change. However, there is a distinct lack of human-centered interfaces, leading to discomfort among occupants This not only results in discomfort, such as visual discomfort experienced due to an oversupply of light, but also a reduction in productivity. In this thesis, a novel dynamic building shading technology is discussed, and the occupant is added directly into the control loop, to discover their preferences, and to avoid visual discomfort and glare. Hence, the main posed research question of this graduation project states: “How can an automated system, consisting of switchable glazing and a system that can sense the needs of the occupant, be used to control glare in an effective manner?” An effective manner of controlling the switchable glazing should both minimise glare, the negative sensation associated with the oversupply of light, and, optimise the use of daylight. The occupant’s facial expression and micro-movements and a lux sensor are combined in a new control strategy, to sense visual discomfort in real-time. Previous studies are analysed to create an office-like environment to test this hypothesis, seeing whether it is possible to predict if one is experiencing glare by one’s facial movements. Two experimental studies are conducted, (i) the first experiment to determine the physical characteristics of the experiment room and (ii) the second experiment to test the novel control system. During the second experiment, a benchmark control strategy and the novel control strategy are tested in the office-like environment and the results are compared. The results from the facial movements show that, in particular, eyebrow movements, may be triggered by light. The results express the potential of adding the face to a control strategy for controlling the amount of light transmitted through the glazing. However, after evaluating the effectiveness of the system, its benefits in terms of daylight and improved availability of view are not clear. For now, at least, in its prototype form, the novel system appeared to be no worse than the benchmark. The desired goal is an interaction between the user and switchable glazing, providing a personal comfortable indoor environment, whilst optimizing the usage of daylight. To reach this, more data has to be collected, however, the following key improvements are suggested; (i) gathering the occupant’s response regarding the level of discomfort immediately (in real-time),(ii) the matter of how to improve the potential for each individual to have their own system is investigated, (iii) the light should be measured via more sensors in different places (for instance fixed to the wall). It should be measured in real-time to determine which one is most beneficial. Furthermore, relation ought to be considered with the architectural design of the building. (iv) The experimental set up mirrors an actual office building to enhance the correlation of the data gathered during such experimental studies, also to study the data with real sunlight, the most common source of glare