Application of control charts for detecting faults in Variable-Air-Volume boxes

This paper describes a fault detection method developed for application to variable-air-volume (VAV) boxes. VPACC (VAV Box Performance Assessment Control Charts) is a fault detection tool that uses a small number of control charts to assess the performance of VAV boxes. The underlying
approach, while developed for a specific type of equipment and control sequence, is general in nature and can be adapted to other types of VAV boxes. VPACC has been tested using emulation,
laboratory, and field data sets. The results are encouraging. VPACC successfully detected each of the faults introduced in the emulation and laboratory testing and also detected two faults that were not intentionally implemented. In addition, no false alarms were identified in the emulation and
laboratory testing. The assessment of VPACC with field data was not as straightforward, however, VPACC alarms for the field data do seem to point to several design and operational issues.