Energy Performance Optimization of Photobioreactor Façades in Commercial Buildings in Hot-Arid Climates (Case Study: Commercial Building in Qom, Iran)

چکیده مقاله

Problem statement: Over recent decades, environmental crises driven by escalating greenhouse gas emissions have increasingly steered the attention of architects and urban planners toward sustainable design and energy-efficient strategies. Among the emerging innovations in this domain is the integration of microalgae-based photobioreactors into building façades. Research objective: This study aims to evaluate the change in annual energy consumption intensity (kWh/m²) of a commercial building located in the hot-arid climate of Qom by applying a photobioreactor façade system and comparing its performance with that of a reference glass façade. Research method: The study adopts a descriptive–analytical approach supported by energy simulation. After reviewing theoretical foundations, relevant photobioreactor technologies, and international case studies, a representative commercial building was modeled. Its annual energy consumption under four façade configurations—single glazing, double glazing, single-skin photobioreactor, and double-skin photobioreactor—was simulated using DesignBuilder software and Qom’s climatic data. Additionally, a sensitivity analysis was conducted on microalgae suspension transparency, the ventilation rate within the cavity of the double-skin system, and window thermal transmittance. Conclusion: The simulation results demonstrate that replacing conventional glazing with photobioreactor panels—particularly the double-skin configuration—significantly reduces annual energy consumption, decreasing from 272.58 to 175.88 kWh/m². The double-skin system also moderated thermal variations across different orientations. Sensitivity analysis indicates that the energy performance of the double-skin photobioreactor façade is predominantly influenced by microalgae suspension transparency and cavity ventilation rate, whereas variations in the window U value had minimal effect on overall energy consumption. The findings are specific to the climatic conditions of Qom and the modeling assumptions applied in DesignBuilder; therefore, further research is needed to evaluate applicability in other climatic contexts.