AbstractBuildings have a significant share in climate change due to their environmental impacts and energy consumption. While embodied carbon and energy of buildings throughout their life cycle can be managed and reduced with strict measures, operational carbon and energy are not easy to target and tackle. One of the components of a building with direct impact on its energy consumption and indoor comfort conditions – e.g. light, glare, temperature, and humidity to name but a few – is the building façade where architectural design manifestations also materialises. Designing building facades is not an easy task as many contradictory variables – from the most aesthetic to the most technical ones – need to be taken into account. This task is even more complex where the building is, more often than not architecturally, required to have a highly- to fully-glazed façade. To fulfil such a demanding task, technological solutions such as Integrated Façade Systems (IFS) have been developed and deployed. IFS are systems where different technological solutions are integrated to improve performance and lower the impact of the building. The research on IFS is scarce and scattered with reference to coverage, scope and focus. Moreover, many different aspects of integration can be considered for IFS, where technology is considered as the integrated element into façade compartments to address energy consumption, solar gain and indoor thermal and visual comfort conditions.
This study investigates the integration of Photovoltaic Shading Devices (PVSD) and High Performance Glazing (HPG) – within the scope of IFS – as a specialised and highly flexible area of research with a promising scope to establish a methodology for a systemic investigation of highly- to fully-glazed façades. The aim of this study is minimising heat and solar gain while maximising natural daylight and electricity generation, which will result in reducing the overall energy and carbon footprints of buildings in general and specifically office buildings in hot and arid climates. This however, is just one of the several application of the proposed methodological approach devised in this study whose application can be extended to other studies within this area but with different objectives. In doing so, this study develops an approach informed by the ‘Systems Theory’ to classify different parameters and variables with a potential impact level on the topic of the study. It uses a sequential combination of qualitative and quantitative methods (but not a mixed method), to first develop a base model and then through simulation measure and evaluate the energy consumption, indoor solar gain and visual comfort of different variations of the designated façade parameters through the boundaries and scope of this research defined through the systemic methodology, to optimise the use of IFS in the design of highly- to fully-glazed office buildings. In-depth and comprehensive analysis of inter-dependency of variables has been carried out, followed by sensitivity analyses to measure the impact of change of parameters and elements of the façade – within the systemic boundaries of this research – on the net energy, heat and solar gain and visual comfort in such buildings.
The methodology developed exclusively for this research can provide a frame of reference as a flexible platform with modular structure which supports full parametric alternatives that can be customised to meet the context specifics of any similar given study. It is envisaged that such methodology provides an unprecedented example which contributes to the existing knowledge, where a multitude of elements, criteria and factors are involved in studies on or around energy and Carbon footprints as well as environmental impacts of buildings. As a secondary contribution, the methodology has been developed, demonstrated and hence can be used as a practical decision support system to help designers make the best design decisions when designing office buildings with highly- to fully-glazed facades in hot and arid climates. With minor systemic adjustments in the modular structure of this methodological frame, both the research and its by-product – the design decision support tool – can be customised and used to assist both researchers and designers for other building types, and in other climatic conditions.
Extended tables of simulation results of 1620 possible combinations of variables for the design and application of IFS in highly- to fully-glazed office buildings in hot and arid climates have been provided which contribute to ongoing development of building codes in the context of this study. The research concludes with some interesting findings which challenge the common understanding of significance and impact of design elements. To name but one example, reducing the impact of one variable (e.g. the inclination angle of the PVSDs) due to its correlation with another variable (e.g. the ratio between the depth of PVSD and the distance between them) to overcome one or more of design constraints (e.g. building orientation) and to provide a multitude of design options for trade-offs between rather contradictory functions, such as reducing energy use, improving daylighting and increasing energy generation.
|Date of Award||Mar 2019|
|Supervisor||Poorang Piroozfar (Supervisor), Neil Ravenscroft (Supervisor) & Ryan Southall (Supervisor)|