Abstract
<title>Abstract</title> <p>Indoor lighting accounts for 15–20% of global building electricity consumption, yet conventional control systems struggle to address energy efficiency, circadian health, and occupant comfort within a unified operational framework. This study presents the design, deployment, and field validation of an integrated smart lighting architecture combining hyper-heuristic optimization, interoperable IoT communication, and Event–Condition–Action automation within a four-layer hierarchical framework. The system was implemented across 12 office zones with 48 tunable LED luminaires in a university building in Riyadh, Saudi Arabia, over 12 weeks. Performance was evaluated through continuous energy metering, melanopic equivalent daylight illuminance measurements, visual illuminance monitoring, and occupant surveys (n = 28). Results demonstrated a 37.8% reduction in lighting energy consumption (from 48.2 ± 3.1 to 30.0 ± 2.6 kWh/day; paired t-test: t(11) = 8.94, p < 0.001, Cohen's d = 2.58, 95% CI: [16.8, 19.6] kWh/day). The system achieved 89.6% daytime circadian compliance (m-EDI ≥ 250 lx; 95% CI: [86.4, 92.3]) and 88.4% occupant satisfaction (one-sample t-test vs. µ₀=4.0: t(27) = 2.47, p = 0.020). The hyper-heuristic layer delivered 93.8% optimization solution quality, outperforming standalone GA (87.3%), PSO (88.1%), and SA (82.6%). The ECA rule engine ensured a mean response time of 1.9 ± 0.6 seconds across 3,668 automation events. Interrupted time series analysis confirmed an immediate level change of -15.2 kWh/day (p < 0.001) and significant slope change (-0.12 kWh/day/week, p = 0.034), indicating sustained intervention effects beyond secular trends. Ablation analysis revealed a synergistic surplus of 4.5 percentage points, confirming emergent efficiency gains from the Hierarchical Dual-Control (HDC) framework that formalizes the temporal decoupling of strategic optimization and tactical rule-based layers. The four-layer architecture provides a replicable, interoperable blueprint for sustainable lighting retrofitting in hot-arid climates.</p>