PhD thesis

Intro: Building energy consumption constitutes 40% of global energy usage and closely correlates with the outdoor microclimate, so it is crucial to delve into the indoor-outdoor interaction mechanism. Firstly, by considering building energy usage as a primary driver within this mechanism, we aim to explore its impact on the urban thermal environment. Secondly, we investigate the influence of Building-Integrated Photovoltaic (BIPV) windows, a renewable energy technology that interfaces with indoor and outdoor environments. Our research will examine the effects of BIPV windows on building energy consumption, urban climate, and the dynamics of indoor-outdoor interaction.

Abstracts: The building sector is responsible for the largest global energy use and anthropogenic emissions, leading to severe impacts on urban heat islands and urban energy systems. However, current urban climate models often poorly represent building energy processes. This dissertation aims to enhance building energy modelling in urban climate simulations by developing and evaluating a coupled building energy modelling and single-layer urban canopy model (BEM-SLUCM), which provides a powerful tool for urban climate modelling. The research quantitively demonstrates the importance of incorporating building energy processes in urban climate models. Without considering building energy processes, SLUCM tends to overestimate canyon air temperature and sensible heat flux, particularly in compact neighbourhoods with higher canyon aspect ratios and building surface fractions.

To identify the relative importance of uncertain parameters that regulate the interaction between buildings and urban climate, we found that implementing energy-efficient building materials and adjusting cooling setpoints can significantly reduce overall energy consumption and mitigate the urban heat island effect. The study also emphasizes the significance of considering urban morphology and canyon geometry in urban planning. As one of the renewable technologies that impact both indoor and outdoor environments, building-integrated photovoltaic (BIPV) windows show potential for improving energy efficiency in different cities and climates, particularly in areas with abundant solar potential. Compared to normal windows, BIPV windows can reduce cooling load but increase heating and lighting demand. Larger window coverage could generate more renewable energy and provide greater savings potential. In addition, BIPV windows can improve thermal comfort, making them a promising solution for sustainable urban design.

To improve urban climate models, future research should bridge the gap between building and meteorology communities, integrate BEM-SLUCM with mesoscale climate models, and explore other sustainable building retrofit measures. This research lays a foundation for future investigations into sustainable energy solutions for buildings and improving the accuracy of urban climate models, ultimately supporting sustainable urban development.