Thermal comfort, daylight, and energy performance of envelope-integrated algae-based bioshading and static shading systems through multi-objective optimization

Abstract

Energy-efficient envelopes integrated with different shading devices, as noticeable passive design strategies, have been of great interest for research studies. However, there is a lack of attention on optimizing envelope-integrated novel algae-based bioshading systems (ABBS) in comparison with other shading devices to enhance buildings’ sustainability-oriented performances. Integrating microalgae culture system with building façade as a state-of-the-art bioshading system is among recent developments in high-performance architecture. Although, challenges/limitations concerning different performances of this technology have not been extensively addressed. The present study conducts a multi-objective optimization framework to investigate the Thermal Comfort Percentage (TCP), Useful Daylight Illuminance (UDI), and Energy Usage Intensity (EUI) in a school building to evaluate the relationship between the performance objectives and design variables (shading characteristics, window-to-wall ratio (WWR)) through comparing different static shading systems and ABBS in the hot (BSh) and cold semi-arid (BSk) climates. The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method was also applied to determine the best design options within Pareto frontiers. Results demonstrated that horizontal louver by 128.52 % TCP, 15.10 % UDI improvement in south-oriented façade in BSk, and overhang with fin (OF) by 18.99 % EUI reduction in southern facade in BSh climates contribute the most to enhance the objective metrics. Also, ABBS was not a stand-first system to enhance all the objective metrics compared to the other shading systems in none of the examined climates. Sensitivity analysis indicated that WWR has the most significant positive impact on EUI compared to the other studied metrics in almost all design options.