Climate-adaptive design of photovoltaic blind ventilation window (PVBVW) for optimal energy saving and daylighting

Semi-transparent photovoltaic windows have attracted considerable interest owing to their dual functionality of delivering natural indoor lighting and generating electricity. However, traditional photovoltaic windows face challenges such as single-function operation, low photoelectric conversion efficiency, and ineffective regulation of indoor lighting conditions. To address these issues, this study introduces an innovative external photovoltaic blind ventilation window (PVBVW), which integrates the core functions of venetian blinds, photovoltaic power generation, and ventilated skin facades. Through seasonal functional modulation, the system optimizes the synergy between lighting, power generation, and thermal regulation. A hybrid approach of numerical simulation and experimental validation was adopted to investigate the annual performance of the PVBVW system in terms of daylighting, thermal comfort, and energy consumption. A comparative analysis was performed to evaluate its performance against traditional windows across three distinct climate zones (Beijing, Hefei, and Guangzhou). Results demonstrate that the PVBVW system achieves annual energy savings of 77.97% in Beijing, 68.29% in Hefei, and 48.90% in Guangzhou, outperforming traditional window system significantly. Furthermore, response surface methodology was utilized for multi-objective optimization under the constraint of sUDI300-2000/50% ≥ 55%, with the objectives of maximizing thermal comfort duration and minimizing net energy consumption. Optimal combinations of design parameters were determined for different climate zones and seasonal scenarios, providing a robust framework for the practical application of the PVBVW system.