Utilising heat transfer simulations to predict thermochromic patterns on 3d-printed façade elements.

Research project by Andreas Körner (2022-2023)

Thermochromic materials are promising for architecture, but their limited UV resistance poses a problem for external applications. Such environmentally responsive smart materials have been studied in various fields ranging from fashion to product design and architecture. Building on previous research by the author, the project aimed to overcome the limitations of thermochromics by exploring heat transfer through solids from external to internal boundaries. Specifically, it investigated an integrated design and evaluation method for combining ceramic 3d-printing and thermochromic coatings for architectural design. In this context, thermochromics are materials that reversibly change their colour relative to changes in surface temperature. The author devised an experimental method to test the hypothesis that heat transfer through a solid can be used to program such a heat-induced colour change. Ceramic 3d-printing was used to fabricate a series of different prototypes. After thermochromic coating, the samples were visually analysed. The results were compared with digital heat transfer and solar heat gain simulations. This method provides an opportunity to visually predict and design thermochromic effects on porous, ceramic 3d-prints. Where previous research was limited to investigating relief geometries that were cnc-milled or cast, this project built on this knowledge and explored much more complex formal and textural prototypes. This novel approach was made possible by using 3d-printing rather than milling. In doing so, the architectural element communicates between indoor and outdoor weather conditions and translates invisible thermal comfort parameters into visible, striated patterns.

Integrated Thermochromic Striation focused on three main aspects: incorporating thermal considerations into digital form generation, using heat-sensitive materials, and creating striped patterns through layering. The project involved a digital and physical approach, with initial geometries created using Cinema4D and optimized for ceramic 3D printing. The prototypes were then coated with thermochromic pigment and analyzed for heat transfer and solar heat gain performance using Autodesk CFD and Ladybug Tools. The results were used to predict the thermochromic response using computer graphics digitally. The project resulted in nine heat-responsive fragments with varying material thickness, form, and intricacy. The prototypes were tested and evaluated, forming the basis for a digital simulation workflow that predicts the thermochromic response of a 3D-printed ceramic facade element. It investigates the role of mass in thermochromic programming, with ceramic pieces retaining heat for a long time and allowing for dynamic modulation. Wall-mounted thermochromic parts can be challenging to mount, but the textures resulting from fabrication enhance the dynamic effect.

Ceramic 3d prints by cera.LAB (Innsbruck).

Funding: Vizerektorat für Forschung (Early-Stage Funding) at Universität Innsbruck

Principal investigator: Andreas Körner
Assistants: Catalina Tripolt and Jacques Biever