Energy Efficiency in Building Retrofitting Using Textile-Based Second-Skin Façades. A Numerical Comparative Analysis Across Iranian, European, and Nordic Climate Zones

The dissertation focuses on enhancing energy efficiency in building retrofitting by utilizing textile-based second-skin façades across different climate zones. The research specifically investigates the performance of these façades in Iranian, European, and Nordic contexts. The thesis begins by addressing the energy consumption of buildings, particularly in Europe, where buildings account for around 40% of total energy use. Retrofitting older structures is vital due to the significant energy loss from outdated building envelopes, many of which are over 50 years old. The second-skin façade (SSF) system includes three main components: (i) an insulation layer on the external surface of the existing building's walls, (ii) an air cavity, and (iii) a external layer. These additional layers improve the performance of the building envelope. While SSFs are recognized for their capacity to enhance energy performance, most existing studies focus on glass or opaque materials. This thesis introduces a novel approach by using flexible, textile materials as the second-skin layer, which is both lightweight and adaptable to various building forms. The study leverages numerical simulations to assess the potential energy savings and reduction in CO2 emissions achieved through this innovative solution. The research methodology comprises case studies from different climate zones: Iran, Europe, and Norway. These diverse climate conditions allow for a comprehensive evaluation of the system’s performance in varying temperature ranges, heating, and cooling demands. The simulations, carried out using the TRNSYS 18 platform, evaluate energy savings, indoor comfort, and environmental impact. The Iranian case study is particularly significant due to its extreme temperature fluctuations, while the European and Norwegian studies emphasize both cooling and heating energy requirements. The results demonstrate that the proposed second-skin façade system provides substantial energy savings, particularly in warmer climates, where cooling demands are high. The textile-based façades significantly reduce solar heat gain, minimizing the need for air conditioning, while maintaining indoor comfort. In colder climates, the façades act as thermal buffers, preventing heat loss and reducing heating energy consumption. Across all case studies, the textile façades contribute to a decrease in CO2 equivalent emissions, aligning with broader climate targets set by the European Union. In conclusion, this dissertation highlights the potential of textile-based second-skin façades as an effective solution for improving energy efficiency in building retrofits. The findings suggest that flexible materials, when used as second-skin layers, offer both architectural and environmental benefits. This research provides a foundation for further exploration of textile façades in building energy performance, particularly in regions with diverse climatic conditions.