“Investigation of faults in air-conditioning systems in commercial buildings: occurrence, diagnostic validation, and energy impacts”
Architectural Engineering PhD Dissertation Defense by Yuxuan Chen
Starts at
9:30 am
Peter Kiewit Institute Room: 250
Target Audiences:
Contact:
The Durham School of Architectural Engineering and Construction, durhamschool@unl.edu
Advised by Dr. David Yuill
In commercial buildings, fault detection and diagnosis (FDD) tools have been developed for detecting and diagnosing faults in building systems, which can provide useful information regarding fault locations and potential causes of faults, so that building operators and facility staff can be notified in time and quickly respond as problems arise. Several studies have demonstrated the energy saving potential with the use of FDD in commercial HVAC systems, and one critical aspect of the considerations of faults is their prevalence which can indicate the commonality of faults over a course of time, and provide insights into fault prioritization. In this study, fault prevalence in HVAC systems is investigated using the fault data collected from six FDD providers in the U.S., and four metrics with respect to different aspects of fault prevalence are developed to quantify the frequency of the faults over specific time periods. When relying on the fault records generated by FDD tools for prevalence analysis, field studies are conducted in selected buildings to validate the fault conditions reported by FDD. Another essential part of this study is to evaluate the energy impacts of the faults. It is common that operational faults in HVAC systems can affect the building energy performance. By simulating selected faults in medium-scale and large-scale commercial buildings through EnergyPlus, impacts with respect to energy consumption and indoor thermal comfort are demonstrated when HVAC system is operating under different faulty conditions.
In commercial buildings, fault detection and diagnosis (FDD) tools have been developed for detecting and diagnosing faults in building systems, which can provide useful information regarding fault locations and potential causes of faults, so that building operators and facility staff can be notified in time and quickly respond as problems arise. Several studies have demonstrated the energy saving potential with the use of FDD in commercial HVAC systems, and one critical aspect of the considerations of faults is their prevalence which can indicate the commonality of faults over a course of time, and provide insights into fault prioritization. In this study, fault prevalence in HVAC systems is investigated using the fault data collected from six FDD providers in the U.S., and four metrics with respect to different aspects of fault prevalence are developed to quantify the frequency of the faults over specific time periods. When relying on the fault records generated by FDD tools for prevalence analysis, field studies are conducted in selected buildings to validate the fault conditions reported by FDD. Another essential part of this study is to evaluate the energy impacts of the faults. It is common that operational faults in HVAC systems can affect the building energy performance. By simulating selected faults in medium-scale and large-scale commercial buildings through EnergyPlus, impacts with respect to energy consumption and indoor thermal comfort are demonstrated when HVAC system is operating under different faulty conditions.