Sensitivity analysis of an automated fault detection algorithm for residential air-conditioning systems

Journal Article · Sat Nov 04 04:00:00 EDT 2023 · Applied Thermal Engineering

DOI:https://doi.org/10.1016/j.applthermaleng.2023.121895· OSTI ID:2274818

Chintala, Rohit ^[1]; Winkler, Jon ^[1]; Ramaraj, Sugirdhalakshmi ^[1]; Jin, Xin ^[1]

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1. National Renewable Energy Laboratory (NREL), Golden, CO (United States)

The state of the art of fault detection and diagnosis (FDD) for residential air-conditioning systems is expensive and not yet amenable to widespread implementation. FDD for homes can significantly reduce utility costs, and increase the lifespan of the equipment. The cost barriers currently, however, make FDD for homes economically unviable for large scale implementation. In prior work, we offered a solution to reduce FDD costs by proposing an automated fault detection algorithm to serve as a screening step before more expensive FDD tests can be conducted. The algorithm uses only the home thermostat and local weather information to identify thermodynamic parameters and detect high-impact air-conditioning faults, including those that occur during equipment installation. We had tested the algorithm on a single EnergyPlus™ model of a home in Orlando, Florida. The thermodynamic parameter identification process is highly nonconvex involving several local optimal solutions. In this paper we propose a novel method to select the best model for fault detection from among the list of local optimal solutions to make the algorithm more robust to homes of different construction, without which the fault detection process would be infeasible. Another unique contribution of the paper is implementing the solution on real-world data. We also bring the algorithm closer to market by testing it on real-world data. We implement the algorithm on data obtained from experiments conducted by the Florida Solar Energy Center (FSEC) on a laboratory home equipped with a heat pump where faults were intentionally added for a period of seven months. The algorithm successfully detected an undercharge fault with 70.6% accuracy, concurrent duct leakage and undercharge faults with 85.2% accuracy, and duct leakage faults with 69.1% accuracy. A sensitivity analysis is also performed on EnergyPlus models of nine types of homes that vary in construction to demonstrate the robustness of the algorithm. Finally, the algorithm achieves an average accuracy of 71% for no-fault condition, 77% for 40% undercharge fault, and 76% for duct-leak fault.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Sustainable Transportation. Bioenergy Technologies Office (BETO)
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 2274818
• Alternate ID(s): OSTI ID: 2216952
• Report Number(s): NREL/JA--5500-83646; MainId:84419; UUID:697e6647-7c8d-40e0-9ce6-a4ed0b731953; MainAdminID:71394
• Journal Information: Applied Thermal Engineering, Journal Name: Applied Thermal Engineering Vol. 238; ISSN 1359-4311
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
automated fault detection
gray-box modeling
residential air-conditioning systems (HVAC)