AC-02-12-3 -- Practical Experiences from Developing and Implementing an Expert System Diagnostic Tool PDF

A building energy management system (BEMS) super-vises, among other tasks, the energy consumption of a building in an automated way. The detection and diagnosis of faults, underperformance, or abnormalities, however, are often is not automated. Underperformance is a deviation from correct operation in terms of energy, comfort, or equipment life. A diagnostic tool for the detection and diagnosis of underperformance aims at assisting building operators. The Performance Audit Tool, based on an expert system, aims at precisely this purpose.

Types of underperformance types to be detected include excessive energy consumption and comfort issues, such as zone temperatures that are too hot or too cold. Their causes may be total or partial component failure, wrong parameter settings, operator errors, undersized system capacity, changes of building, zone usage, etc. As PAT does not receive user input during the audit, it will in many cases be unable to indicate the exact cause of a detected underperformance.