Developing an Integrated 3D Printed Façade with Complex Geometries for Active Temperature-Control (2018-03)¶

future buildings. AM methods have advantages over other production processes, such as great freedom of form, shape complexity, scale and material use. Because the freedom in geometric complexity applies also to the inner part of the products manufactured with additive processes, it is possible to customize inner geometries to integrate multi-functionalities. Products with multiple functions integrated are interesting for the building industry not only for the multi-functionality but also for the potentials of 3d printing these components in large scale. Complexity in form and function is observed in the façade which is one of the most challenging parts of a building. Thus, an increasing interest in the application of advanced building envelope solutions can be seen both in research activities and in industrial developments. Given the potential of 3d printing technology to generate complex geometries and include multiple functionalities, there are ongoing developments towards new or improved materials, production technologies and function integration. However, the focus of most research is directed towards the mechanical properties of materials and their use as part of load-bearing and construction systems. The integration of additional aspects is often achieved with post processing and the use of multiple materials. There is an important need for research into the limits of the performances specially for thermal insulation and building physics that can be combined in one component and one production technology. Moreover, there is need for additional investigation in the maximum printable size of façade components and on the challenges and the potentials to 3d print large-scale components. To this end, the research project SPONG3D aims to develop a 3D-printed façade panel that integrates insulating properties with heat storage in a complex, mono-material geometry. The present paper gives an overview of the development process that took into consideration different aspects that the façade module needs to address and the challenges for the printing process, such as material use, printing time and scale. Those considerations and the thermal performance requirements drove the design iterations and tests and determined decisions related to the geometry and the printing technology selection. The interaction of these aspects resulted in the design and manufacturing of a prototype, which proves the potential of functions integration in such a façade, but also highlights the limitations and the need for further developments. The latest prototypes consist of 2 items. One working prototype (size: 660 mm(height)×200mm(width)×100 mm(thickness)) in which the water circulation is being tested. One prototype for demonstration (size:750 mm(height)×500mm (width)×360 mm(thickness)). At the same time, simulations were run to understand the thermal effects of the system on indoor spaces in different climates. With focus on the 3D printing process, the paper will present and discuss the results of each phase; as well as the design iteration that led to the current prototypes. Moreover, the paper will critically reflect on the challenges encountered during the research and will discuss the current limits of the work. The research was conducted during 12 months of interdisciplinary teamwork, involving researchers from the façade discipline, thermal engineering and building physics, structural design, digital design and production.