A Simulation-Calibrated Digital Twin Framework for Real-Time Energy Management and Fault Detection in Commercial Buildings
University of West London, London, United Kingdom
Abstract: This study presents a simulation-calibrated digital twin framework for real-time energy management and fault detection in commercial buildings. Commercial buildings often consume more energy than expected because of HVAC faults, sensor drift, control problems, and differences between assumed and actual occupancy patterns. These issues are not always detected by conventional building management systems, which can lead to unnecessary energy use and delayed maintenance actions. The proposed framework is designed as a three-layer digital twin process that combines building simulation, machine learning, and anomaly detection. The first layer develops a high-fidelity EnergyPlus model calibrated using sub-hourly building management system data and assessed against ASHRAE Guideline 14 criteria. The second layer uses machine learning surrogate models, including XGBoost and Random Forest, to support fast energy prediction at the zone level. These surrogate models reduce the computational burden of running full simulation models while keeping useful prediction accuracy for operational use. The third layer compares live sensor readings with digital twin forecasts and applies Isolation Forest and autoencoder-based anomaly detection to identify possible faults in real time. The framework is tested using a UK commercial hotel archetype. The results show calibrated model performance with NMBE below 5% and CV-RMSE below 15%, surrogate model R² values above 0.85, and fault detection accuracy of 91% with a false-positive rate below 8%. The digital twin-based scheduling approach also estimates energy reduction of 12–18% compared with baseline operation. The study shows that combining simulation calibration, machine learning inference, and real-time fault detection can support building energy management, reduce avoidable energy use, and improve operational decision-making. The proposed framework can be used as a repeatable process for future smart building applications and can support the development of net-zero-ready commercial building operations through better monitoring, prediction, and control.
Keywords: Digital twin, building energy management, fault detection, EnergyPlus, machine learning, anomaly detection, HVAC optimisation, building calibration, smart buildings, net-zero
