A Cemesova, Y Rezgui, C J. Hopfe
Possibilities and challenges created by a smart material in building performance simulation
Abstract: Smart materials are predicted to ‘revolutionise’ the A/E/C industry. They are supposed to enable a building to change colour, shape, size and opacity. However, past research shows that smart materials are still not used very often in engineering applications to their full potential. In this publication we advocate that materials should not be only chosen for simple properties such as visual, physical and insulating characteristics, but for capabilities such as being able to save/generate energy, store information, and to react to stimuli from their local environment. Therefore, this paper will research into the addition of SolaVeil to a window, its physical configuration and the possibility to model and analyse it through Building Performance simulation (BPS). This material is primarily designed to eliminate glare and redirect light. As a result it can reduce energy use caused by air conditioning and artificial lighting systems. This paper researches into the behaviour of SolaVeil in a computer simulation using two different case studies. The first will compare how changing the width but maintaining the reflective area affects illuminance distribution, and the second will determine which physical properties of SolaVeil are most effective. Finally, conclusions are drawn based on the case studies and it is shown that smaller width light shelves are the most suitable for an anti glare product. It is also determined that for SolaVeil to minimise glare in a room without compromising illuminance levels, it should have a light shelf angle of 40 degrees, cover between 40-60% of a window and its strips should be spaced 5mm.
Keywords: SolaVeil, smart materials, building system design, illumination.
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Gokce Ozcelik, Burcin Becerik-Gerber, Ali Ghahramani and Yuchao Wang
Can Immersive Virtual Environments Be Used for Understanding Occupant-System Interactions Under Thermal Stimuli?
Abstract: OccupantsÕ interactions with building systems, as well as occupant-related factors considerably influence a buildingÕs energy consumption. However, understanding occupant-system interactions related to thermal changes in built environments could be cumbersome due to the resources needed to create these environments or the resources needed for conducting controlled experiments in existing Physical Environments (PEs). One avenue is to use Immersive Virtual Environments (IVEs) where occupantsÕ interactions with the built environment are measured in the context of thermal stimuli. However, for validating the adequacy of using IVEs for understanding occupant interactions with building systems and/or elements, it is imperative to first investigate if IVEs are proper representations of PEs. In this study, we benchmark IVEs to the PEs with regards to user perceptions relating to thermal stimuli. In a human subject experiment, we use surveys and subjective thermal votes both in the IVE and PE, where participants experience both hot and cold indoor thermal conditions. Perceived thermal comfort and satisfaction votes are analysed by using paired t-tests and ANOVA. The change parameters are defined for identifying the direction of perceived thermal comfort and satisfaction. Statistical inferences show that change in occupantsÕ perceived thermal comfort and satisfaction in IVE and PE are not significantly different, and direction of the change is positive in majority of the cases (i.e., 100% of the participants were comfortable in PE, almost 95% of the participants were comfortable in IVE, 79 % were satisfied in PE, 74% were satisfied in IVE at the end of the experiment).
Keywords: Immersive Virtual Environment; Virtual Reality; Physical Environment; Thermal Perception; Building Systems; Occupant-Building Systems Interactions
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