Evaluating the Impact of Integrated Reflective Louver Daylighting and LED Dimming Control Systems on Visual Comfort and Cognitive Performance in Office Environments

Abstract

The drive towards Zero-Energy Buildings (ZEB) necessitates optimized lighting energy solutions. Integrated technologies combining daylight-concentrating louvers and LED Dimming Control have been shown to significantly reduce energy consumption. However, the impact of these dynamic lighting changes on occupants' visual comfort and work performance remains a research gap. This study aims to evaluate the balance between energy efficiency and occupant comfort by integrating the Daylight Glare Probability (DGP) into the control algorithm. Three lighting scenarios were tested in a simulated office mock-up: A (Baseline: LED ON/OFF), B (Energy Optimization: Dimming based on average illuminance), and C (Comfort Optimization: Dimming based on both illuminance and DGP<0.35). The results demonstrate that Scenario C achieved an average energy saving of 75.7% compared to Scenario A, while successfully maintaining the Daylight Glare Probability (DGP) at an acceptable level (DGP≤0.35). Crucially, Scenario C resulted in an 8.1% faster cognitive reaction time and 50% fewer errors compared to Scenario B, proving that a comfort-prioritized control strategy not only saves energy but also enhances cognitive performance. The study proposes a dual-factor (Illuminance, DGP) control model as the sustainable operational standard for future ZEB lighting systems.