Abstract

Buildings are at the pivotal centre of our lives. We spend, on average, 87-90% of our time in buildings. The characteristics of a building, its design, its look and feel as well as its technical standards not only influence our productivity, our wellbeing, our moods and our interactions with others, but they also define how much energy is consumed in and by a building, particularly for heating, ventilation, cooling and lighting. The envelope of a building has an important and direct effect on its overall performance and whole-life cost. Glazing is particularly critical because it is the most vulnerable envelope element to heat gain and heat loss that counts for around 42% of the total building energy consumption (U.S Department of Energy). However, con-ventional static glazing technologies have relatively poor per-formance characteristics which cause significant heat losses during winter and undesired heat gain in summer. This project aims to develop an innovative high-performance closed cavity facade (CCF) prototype, combining static and dynamic glazing technologies with integrated solar radiation control features and strategies in order to, besides achieving a high thermal resistance, also be able to dynamically control (harvesting or rejecting) the incident solar radiation, optimising the incoming thermal and lighting flows. In this regard, the main objective of this research is to investigate the thermal and visual performance of glazing technologies and glazing systems’ solu-tions, in the context of low-energy office buildings with large sea-sonal heating and cooling loads variations, without compromising the indoor environmental quality (IEQ). Experimental research will be used, in combination with nume-rical simulations and optimisation methods (Figure 1), to assess and optimise the overall performance of glazing systems and associated solar radiation control features. The ultimate aim is to devise and develop a multi-functional high-performance closed cavity facade prototype, incorporating new adaptive features like switchable technologies and advanced solar control strategies, in order to achieve optimised configuration and geometry for maximising energy saving in office buildings whilst minimising the whole-life cost and ensuring the required IEQ level. At a preliminary case study, simulating the performance of the MATE Lab (Mobile Adaptive Technologies Experimental Lab) at the University of Cambridge, two scenarios were studied, one with CCF incorporating shading system and control strategies and the other one without any shading features. The study concluded that the employed CCF with incorporated shading system and control strategy resulted in a yearly reduction of 68% of the cooling energy consumption compared to the conventional insulated double glazing units.