{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,2]],"date-time":"2026-04-02T16:08:35Z","timestamp":1775146115918,"version":"3.50.1"},"reference-count":35,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2018,11,14]],"date-time":"2018-11-14T00:00:00Z","timestamp":1542153600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100012774","name":"Innovationsfonden","doi-asserted-by":"publisher","award":["COORDICY"],"award-info":[{"award-number":["COORDICY"]}],"id":[{"id":"10.13039\/100012774","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003329","name":"Ministerio de Econom\u00eda y Competitividad","doi-asserted-by":"publisher","award":["DPI2017-88403-R"],"award-info":[{"award-number":["DPI2017-88403-R"]}],"id":[{"id":"10.13039\/501100003329","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Buildings represent a significant portion of global energy consumption. Ventilation units are complex components, often customized for the specific building, responsible for a large part of energy consumption. Their faults impact buildings\u2019 energy efficiency and occupancy comfort. In order to ensure their correct operation, proper fault detection and diagnostics methods must be applied. Hardware redundancy, an effective approach to detect faults, leads to increased costs and space requirements. We propose exploiting physical relations inside ventilation units to create virtual sensors from other sensors\u2019 readings, introducing redundancy in the system. We use two different measures to detect when a virtual sensor deviates from the physical one: coefficient of determination for linear models, and acceptable range. We tested our method on a real building at the University of Southern Denmark, developing three virtual sensors: temperature, airflow, and fan speed. We employed linear regression models, statistical models, and non-linear regression models. All models detected an anomalous strong oscillation in the temperature sensors. Readings fell outside the acceptable range and the coefficient of determination dropped. Our method showed promising results by introducing redundancy in the system, which can benefit several applications, such as fault detection and diagnostics and fault-tolerant control. Future work will be necessary to discover thresholds and set up automatic fault detection and diagnostics.<\/jats:p>","DOI":"10.3390\/s18113931","type":"journal-article","created":{"date-parts":[[2018,11,14]],"date-time":"2018-11-14T10:58:22Z","timestamp":1542193102000},"page":"3931","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":48,"title":["A Method for Fault Detection and Diagnostics in Ventilation Units Using Virtual Sensors"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3801-5617","authenticated-orcid":false,"given":"Claudio Giovanni","family":"Mattera","sequence":"first","affiliation":[{"name":"Center for Energy Informatics (CFEI), Maersk Mc-Kinney Moller Institute (MMMI), University of Southern Denmark (SDU), 5230 Odense, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7827-2896","authenticated-orcid":false,"given":"Joseba","family":"Quevedo","sequence":"additional","affiliation":[{"name":"Center for Supervision, Security and Automatic Control (CS<sup>2<\/sup>AC), Polytechnic University of Catalonia (UPC), 08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6090-1538","authenticated-orcid":false,"given":"Teresa","family":"Escobet","sequence":"additional","affiliation":[{"name":"Center for Supervision, Security and Automatic Control (CS<sup>2<\/sup>AC), Polytechnic University of Catalonia (UPC), 08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2858-8400","authenticated-orcid":false,"given":"Hamid Reza","family":"Shaker","sequence":"additional","affiliation":[{"name":"Center for Energy Informatics (CFEI), Maersk Mc-Kinney Moller Institute (MMMI), University of Southern Denmark (SDU), 5230 Odense, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3039-1845","authenticated-orcid":false,"given":"Muhyiddine","family":"Jradi","sequence":"additional","affiliation":[{"name":"Center for Energy Informatics (CFEI), Maersk Mc-Kinney Moller Institute (MMMI), University of Southern Denmark (SDU), 5230 Odense, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,11,14]]},"reference":[{"key":"ref_1","unstructured":"European Parliament, Council of the European Union (2010). 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