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Rule-Based Fault Detection Method for Air Handling Units.

pdf icon Rule-Based Fault Detection Method for Air Handling Units. (4513 K)
Schein, J.; Bushby, S. T.; Castro, N. S.; House, J. M.

Energy and Buildings, Vol. 38, No. 12, 1485-1492, December 2007.


Department of Energy, Washington, DC


air handling units; fault detection; diagnostics; building automation; direct digital control; energy management system


Air handling unit performance assessment rules (APAR) is a fault detection tool that uses a set of expert rules derived from mass and energy balances to detect faults in air handling units (AHUs). Control signals are used to determine the mode of operation of the AHU. A subset of the expert rules which correspond to that mode of operation are then evaluated to determine whether a fault exists. APAR is computationally simple enough that it can be embedded in commercial building automation and control systems and relies only upon the sensor data and control signals that are commonly available in these systems. APAR was tested using data sets collected from a "hardware-in-the-loop" emulator and from several field sites. APAR was also embedded in commercial AHU controllers and tested in the emulator.