Performance investigation of a climate-active top lighting cell developed with generative processes and digital manufacturing
Authors:   , Lucarelli Caio de Carvalho 
Published: August 2024

Building electricity demands have risen due to floor area growth, increased indoor time, overreliance on artificial systems, aging infrastructures, and distribution bottlenecks. Since 2017, energy expenses have increased up to 20%, totalizing 40% of worldwide requirements and 36% of carbon emissions in the early 2020s. In this scenario, early-stage building design and performance simulation demonstrate the highest potential and lowest cost for energy saving. Among all building subsystems, enclosures are multicriteria mediators that partake in most indoor/outdoor energy flow, naturally conditioning buildings, and promoting occupant comfort. However, as prescriptive solutions, they only operate within predetermined environmental thresholds and cannot account for environmental dynamicity or long-term climate changes. Conversely, climate-active building envelopes potentially improve occupants’ comfort in real-time, responding to environmental fluctuations while maintaining acceptable levels of energy consumption. Although their ideation, design, simulation, and materialization are still complex, their various iterations can lead to more optimal solutions. Thus, there is a need to address how to design, operate, and maintain active envelopes and access their adaptation, behavior, performance parameters, and materialization. This research covered the ideation, whole-building environmental performance simulation, design, and manufacturing process of a climate-active top lighting cell. It assessed its contributions to human visual and thermal comfort and its optical and structural properties before and after desktop digital manufacturing. It followed a research-through-design and investigated a design- for-manufacturing-and-assembly workflow to help solve the oversimplification of simulations for active typologies, still employing low computational time and cost via iterative simulation and post selection instead of design optimization. As the main results, this study offered an integrative theoretical background on climate-active skins and a preamble for future active building classifications. Further, it created a more comprehensive parametric modeling and simulation workflow for building motion and real-time simulation, defined a variance-based simplification strategy for motion constraints, and demonstrated the incapacity of current simulation approaches (that only consider solstices and equinoxes as key dates) to represent the dynamicity and performance of active systems. This research also evaluated various processes within the design-for-manufacture approach, assessing the visual and structural properties of thermoplastics as end-use materials for physical prototypes and potential experiments to complement or replace software-intensive or time-consuming applications such as luminance- based high dynamic range imaging for daylight assessment and standard material degradation. Finally, this Thesis is an extensively documented and replicable research of a simulation and experiment-based digital modeling and physical manufacturing process for a cyber-physical system that acts upon environmental sensing to potentialize human comfort within buildings. Keywords: Research-through-design; design-for-manufacture-and-assembly; top lighting; climate-active building envelopes.