In the 21st century, the energy sustainability era, climate adaptive building shells (CABS) became an appealing architectural application. Such appeal is due to the ability of such shells to move and react mechanically (macro-scale CABS) to external energy stimuli; which can control different building envelope aspects such as its thermal loads and daylight exposure. However, such moving ability intrinsically involves using sensor-actuator systems which use electric energy to move the envelope’s components. Thus, for the sustainability trend, it is appealing to use a building envelope material that directly changes its form due to thermal loads (renewable solar energy) without electricity; shape memory alloys (SMAs).
Thus, the research focuses on simulating a two-way SMA (can remember two shapes) building envelope using Grasshopper tool (Ladybug and Honeybee plugins) upon two steps. First, simulating the SMA building envelope form change; the heat transfer equation –using solar thermal loads and dry bulb temperatures- is used to simulate a macro-scale form transformation of a Nickel Titanium Zirconium SMA (NiTiZr) southern building envelope panel monthly. Such simulation aims to showcase the potential form change of SMAs based on temperature changes without going into the technicalities of designing an exposed SMA spring actuator. Second, the amount of thermal loads upon a sample southern building envelope is calculated when applying an extra skin of the NiTiZr paneling. Such result is finally compared to a traditional static shading over sample selected days of the year.
The research’s results aim to highlight a potential material application to explore; relevant to using renewable solar energy. Furthermore, the research concludes with an approach to use exposed SMA spring actuators to reach similar results to the simulation. Such approach can minimize the amount of SMAs to be used in envelopes compared to the NiTiZr panelling, while reaching similar zero electricity results.