Performance study of the one-dimensional Mirror Array window with dynamic reflective control based on a multidimensional coordinated evaluation method

In response to the difficulty that conventional smart windows and shading systems, which rely on single-objective control strategies, cannot simultaneously satisfy daylighting, visual comfort, and thermal comfort, we propose a One-Dimensional Mirror Array Window (ODMA Window). This window uses an array of independently rotatable mirrors within the glazing cavity to dynamically redirect direct sunlight onto diffuse surfaces such as ceilings, thereby enabling coordinated control of daylight and solar heat gain by manipulating the spatial path of incoming light. A multidimensional evaluation method is developed, incorporating spatial Useful Daylight Illuminance (sUDI), Daylight Glare Probability (DGP), and Predicted Mean Vote (PMV). The method introduces the Joint Acceptability Rate (JAR) as a core metric, defined as the annual fraction of hours during which daylighting, visual comfort, and thermal comfort all simultaneously satisfy their predefined acceptability thresholds. Annual hourly simulations are performed using the Radiance and EnergyPlus platforms for a typical office in China's Hot-Summer and Cold-Winter Region. Compared to a conventional window (double-glazed window), the ODMA Window increases the annual average sUDI by 44%, reduces total energy consumption by 13.3% (including a 14.6% reduction in cooling energy), increases Thermal Comfort Percentage (TCP) by 44.2%, and improves the JAR by an average of 14.83 percentage points. The ODMA Window effectively coordinates daylighting, visual comfort, and thermal comfort, offering an innovative pathway for windows to transition from “passive light transmission” to “active daylight control.”