• Proactive FDD targets VAV AHU faults at early stages. • Auto-commissioning overcomes manual limitations with data-driven performance tests. • Active testing utilizes BAS bi-directional interactions for ongoing commissioning. • Auto-commissioning reveals both hardware and control-related system issues. Maintaining reliable and efficient operation of HVAC systems remains a challenge in commercial buildings. Conventional commissioning and recommissioning practices are resource-intensive and infrequent, allowing faults to persist unnoticed for extended periods. This paper presents a system-level auto-commissioning (AC) framework to proactively detect hard and soft faults in variable air volume (VAV) air handling unit (AHU) systems. Hard fault tests target hardware-related problems including mixing box damper faults, and heating/cooling coil malfunctions. Complimentary soft fault tests diagnose control errors related to state of operation, mode of operation, and supply air temperature setpoint (T SA,SP ) and duct static pressure setpoint (P duct,SP ) reset logic. Implementation of the framework in an occupied building successfully revealed a leaky outdoor air damper, an inefficient economizer sequence, and deficiencies in T SA,SP /P duct,SP reset strategies. The results demonstrated the capability of the framework to provide actionable diagnostic insights, reduce reliance on manual inspection, and enhance operational efficiency through early fault detection.
Parsaei et al. (Tue,) studied this question.