Glazing systems with Parallel Slats Transparent Insulation Material (PS-TIM): Evaluation of building energy and daylight performance

Being responsible for a significant proportion of total heat loss in façade dominated buildings, the design and specification of the envelope, particularly the building's glazing system, is a key factor in determining overall energy consumption. To address this, an innovative double glazed façade system comprising parallel transparent/translucent plastic slats sandwiched between the glass panes to form a Parallel Slat Transparent Insulation Material (PS-TIM) system is proposed as a potential solution. This PS-TIM system reduces heat transfer between the glazing panes whilst maintaining access to solar radiation and daylight. The presence of the PS-TIM structure significantly affects the thermal and optical performance of the window system in which it is employed. This presents a further significant challenge when trying to predict its performance using dynamic building simulation approaches. Using a typical small office as a case study subject to varying climatic conditions, we investigate the thermal and optical behaviour of a range of PS-TIMs with respect to their daylight and energy performance. We find that when compared to a conventional double glazed system, the application of PS-TIMs can result in a more visually comfortable and uniformly lit environment, which might be desired in an office space, and, in the specific case of the small office under test, can result in a reduction in energy consumption of up to 35.8%. Furthermore, having explored the performance of the system in response to varying climatic conditions, we also present some advice as to how architects and engineers might apply PS-TIMs to window systems or glazed façades.