Integrating illuminance and energy evaluations of cellular automata controlled dynamic shading system using new hourly-based metrics

摘要

In cooling-dominant climates, the solar heat gain due to sunlight is inevitable, and should be considered when designing energy-efficient façades. This research explores the potential contribution of utilizing monotonous-free Elementary Cellular Automata patterns as climate-adaptive shading systems, to be applied on buildings’ façades in order to mitigate the undesirable impacts by excessive solar penetration in cooling-dominant climates. It also presents a new approach for evaluating the daylighting performance and energy demand for the dynamic shading systems at the early stages of design. Grasshopper is exploited for parametric modeling of Elementary Cellular Automata patterns. The methodological procedure is realized through two main phases. The first evaluates all 256 Elementary Cellular Automata possible rules to elect the ones with random patterns, and to ensure an equitable distribution of the natural daylight in internal spaces. The computational simulations are then conducted in the second phase using DIVA-for-Rhino and Archsim to evaluate the performance of the elected Elementary Cellular Automata patterns that are applied as dynamic shadings. Based on the newly developed hourly-based metrics: Hourly Daylight Illuminance (HDI300/HOY), Hourly Sunlight Illuminance (HSI3000/HOY), and Hourly Energy Consumption (HEC), the adaptive façade variation configuration could be formalized that maximizes daylighting and minimizes energy demand. The simulation results showed that the adaptive façade outperformed the static shading configurations, and exhibited its ability to obtain adequate level of natural daylighting, while mitigated the undesirable impacts of excessive solar penetration, and maintained a minimized amount of cooling load and artificial lighting energy demands throughout the year. This developed tool can aid architects navigating climate-responsive façade designs in order to promote the indoor environmental quality in cooling-dominant climates, in addition to redefine the evaluation criteria to meet their local building performance requirements, and improve the architectural aesthetics and human health.