Sequential rule based algorithms for temperature sensor fault detection in air handling units

Diagnostic Bayesian networks for diagnosing air handling units faults – Part II: Faults in coils and sensors

“…The rule-based methods are advantageous in that only a few sensors are adopted in each rule. However, the rulebased methods are not good for application in sensor fault diagnosis [24]. The challenges of sensor fault diagnosis for AHUs are mostly from the lack of information.…”

A Quantitative Model-Based Fault Detection & Diagnostics (FDD) System for Zone-Level Inefficiencies

“…Furthermore, this fault type may also be increasing in importance with the recent movement from mechanical control systems to integrated software-dominated control systems. [17] Incorrect SAT set-point and wrong AHU mode activated Building [18] Offsets in return, outdoor, mixed and supply air temperature (SAT) sensors Building [7] Condenser fouling Building [19] Condenser and evaporator fouling Building [20,21] Heat exchanger fouling Building [22] Condenser and evaporator fouling, and capacity, energy efficiency ratio (EER), sensible heat ratio (SHR) and seasonal energy efficiency ratio (SEER) degradation Building [23] Any soft faults in a cooling coil subsystem Building [24] Any soft faults in a mechanical draft-counter flow CT Building [13] AHU economizer Building [25] AHU and heating system degradation Building [26,27] Whole building components, e.g. AHUs and meters Building [28] Chiller plant, boiler plant and AHU Building…”

“…The qualitative model-based techniques utilize either a rule-based system or qualitative physics [37,39]. Rule-based systems use a set of if-then statements that consider the equipment control limits [17]. A sequential rule set for the utilization in an FDD tool was developed by Yang, Cho, Tae and Zaheeruddin (2008) [17].…”

“…Rule-based systems use a set of if-then statements that consider the equipment control limits [17]. A sequential rule set for the utilization in an FDD tool was developed by Yang, Cho, Tae and Zaheeruddin (2008) [17]. In particular a rule from Yang et al (2008) [17] can be used to display how this type of FDD tool functions.…”

“…A sequential rule set for the utilization in an FDD tool was developed by Yang, Cho, Tae and Zaheeruddin (2008) [17]. In particular a rule from Yang et al (2008) [17] can be used to display how this type of FDD tool functions. The rule states that if equation 2.1 is true, there is a fault in the system [17].…”