{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,5]],"date-time":"2026-04-05T10:26:19Z","timestamp":1775384779439,"version":"3.50.1"},"reference-count":31,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2025,6,4]],"date-time":"2025-06-04T00:00:00Z","timestamp":1748995200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Association for the Development of Industrial Aerodynamics (ADAI)","award":["UIDB\/50022\/2020"],"award-info":[{"award-number":["UIDB\/50022\/2020"]}]},{"name":"Association for the Development of Industrial Aerodynamics (ADAI)","award":["UIDP\/50022\/2020"],"award-info":[{"award-number":["UIDP\/50022\/2020"]}]},{"name":"Association for the Development of Industrial Aerodynamics (ADAI)","award":["LA\/P\/0079\/2020"],"award-info":[{"award-number":["LA\/P\/0079\/2020"]}]},{"name":"Associate Laboratory of Energy, Transports and Aeronautics (LAETA)","award":["UIDB\/50022\/2020"],"award-info":[{"award-number":["UIDB\/50022\/2020"]}]},{"name":"Associate Laboratory of Energy, Transports and Aeronautics (LAETA)","award":["UIDP\/50022\/2020"],"award-info":[{"award-number":["UIDP\/50022\/2020"]}]},{"name":"Associate Laboratory of Energy, Transports and Aeronautics (LAETA)","award":["LA\/P\/0079\/2020"],"award-info":[{"award-number":["LA\/P\/0079\/2020"]}]},{"name":"Portuguese Foundation for Science and Technology (FCT)","award":["UIDB\/50022\/2020"],"award-info":[{"award-number":["UIDB\/50022\/2020"]}]},{"name":"Portuguese Foundation for Science and Technology (FCT)","award":["UIDP\/50022\/2020"],"award-info":[{"award-number":["UIDP\/50022\/2020"]}]},{"name":"Portuguese Foundation for Science and Technology (FCT)","award":["LA\/P\/0079\/2020"],"award-info":[{"award-number":["LA\/P\/0079\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Air"],"abstract":"<jats:p>This study investigates the performance of different demand-controlled ventilation strategies for improving indoor air quality while optimizing energy efficiency. The experimental research was conducted at the Indoor Live Lab at the University of Coimbra using a smart window equipped with mechanical ventilation boxes, occupancy sensors, and a real-time CO2 monitoring system. Several occupancy-based and CO2-based ventilation control strategies were implemented and tested to dynamically adjust ventilation rates according to real-time indoor conditions, including (1) occupancy period-based control, (2) occupancy level-based control, (3) ON-OFF CO\u2082-based control, (4) multi-level CO\u2082-based control, and (5) modulating CO\u2082-based control. The results indicate that intelligent control strategies can significantly reduce energy consumption while maintaining indoor air quality within acceptable limits. Among the CO\u2082-based controls, strategy 5 achieved optimal performance, reducing energy consumption by 60% compared to the simple ON-OFF strategy, while maintaining satisfactory indoor air quality. Regarding occupancy-based strategies, strategy 2 showed 58% energy savings compared to the simple occupancy period-based control, but with greater CO\u2082 concentration fluctuation. The results demonstrate that intelligent DCV systems can simultaneously reduce ventilation energy use by 60% and maintain compliant indoor air quality levels, with modulating CO\u2082-based control proving most effective. The findings highlight the potential of integrating sensor-based ventilation controls in office spaces to achieve energy savings, enhance occupant comfort, and contribute to the development of smarter, more sustainable buildings. Future research should explore the integration of predictive analytics and multi-pollutant sensing to further optimize demand-controlled ventilation performance.<\/jats:p>","DOI":"10.3390\/air3020017","type":"journal-article","created":{"date-parts":[[2025,6,4]],"date-time":"2025-06-04T11:14:12Z","timestamp":1749035652000},"page":"17","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Experimental Assessment of Demand-Controlled Ventilation Strategies for Energy Efficiency and Indoor Air Quality in Office Spaces"],"prefix":"10.3390","volume":"3","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7167-6871","authenticated-orcid":false,"given":"Behrang","family":"Chenari","sequence":"first","affiliation":[{"name":"Univ Coimbra, ADAI, Department of Mechanical Engineering, Rua Lu\u00eds Reis Santos, P\u00f3lo II, 3030-788 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3500-0188","authenticated-orcid":false,"given":"Shiva","family":"Saadatian","sequence":"additional","affiliation":[{"name":"Univ Coimbra, ADAI, Department of Mechanical Engineering, Rua Lu\u00eds Reis Santos, P\u00f3lo II, 3030-788 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0739-9811","authenticated-orcid":false,"given":"Manuel","family":"Gameiro da Silva","sequence":"additional","affiliation":[{"name":"Univ Coimbra, ADAI, Department of Mechanical Engineering, Rua Lu\u00eds Reis Santos, P\u00f3lo II, 3030-788 Coimbra, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Aguado, A., Rodr\u00edguez-Sufuentes, S., Verdugo, F., Rodr\u00edguez-L\u00f3pez, A., Figols, M., Dalheimer, J., G\u00f3mez-L\u00f3pez, A., Gonz\u00e1lez-Colom, R., Badyda, A., and Fermoso, J. (2025). Verification and Usability of Indoor Air Quality Monitoring Tools in the Framework of Health-Related Studies. Air, 3.","DOI":"10.3390\/air3010003"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Correia, G., Rodrigues, L., Afonso, M., Mota, M., Oliveira, J., Soares, R., Tom\u00e1s, A.L., Reichel, A., Silva, P.M., and Costa, J.J. (2022). SARS-CoV-2 air and surface contamination in residential settings. Sci. Rep., 12.","DOI":"10.1038\/s41598-022-22679-y"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1426","DOI":"10.1016\/j.rser.2016.01.074","article-title":"Towards sustainable, energy-efficient and healthy ventilation strategies in buildings: A review","volume":"59","author":"Chenari","year":"2016","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"196","DOI":"10.3390\/air1030015","article-title":"Using Low-Cost Sensing Technology to Assess Ambient and Indoor Fine Particulate Matter Concentrations in New York during the COVID-19 Lockdown","volume":"1","author":"Holder","year":"2023","journal-title":"Air"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Shao, Z., Wu, C., Shao, Q., Yang, J., and Xie, M. (2024). Prevalence of Sick Building Syndrome Symptoms in Residents During the COVID-19 Pandemic\u2014A Case Study of Suzhou City, China. Buildings, 14.","DOI":"10.3390\/buildings14113388"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Wang, M., Li, L., Hou, C., Guo, X., and Fu, H. (2022). Building and Health: Mapping the Knowledge Development of Sick Building Syndrome. Buildings, 12.","DOI":"10.3390\/buildings12030287"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Honan, D., Gallagher, J., Garvey, J., and Littlewood, J. (2024). Indoor Air Quality in Naturally Ventilated Primary Schools: A Systematic Review of the Assessment & Impacts of CO2 Levels. Buildings, 14.","DOI":"10.3390\/buildings14124003"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Pourtangestani, M., Izadyar, N., Jamei, E., and Vrcelj, Z. (2024). Linking Occupant Behavior and Window Design through Post-Occupancy Evaluation: Enhancing Natural Ventilation and Indoor Air Quality. Buildings, 14.","DOI":"10.3390\/buildings14061638"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Tronchin, L., Fabbri, K., and Bertolli, C. (2018). Controlled Mechanical Ventilation in Buildings: A Comparison between Energy Use and Primary Energy among Twenty Different Devices. Energies, 11.","DOI":"10.3390\/en11082123"},{"key":"ref_10","unstructured":"(2025, March 28). Proposal for a Directive of the European Parliament and of the Council Amending Directive 2010\/31\/EU on the Energy Performance of Buildings. COM (2016) 765 Final. Available online: http:\/\/eur-lex.europa.eu\/resource.html?uri=cellar:4908dc52-b7e5-11e6-9e3c-01aa75ed71a1.0023.02\/DOC_1&format=PDF."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1685","DOI":"10.3390\/en7031685","article-title":"Evaluation of Visitor Counting Technologies and Their Energy Saving Potential through Demand-Controlled Ventilation","volume":"7","author":"Kuutti","year":"2014","journal-title":"Energies"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Chaudhari, P., Xiao, Y., Cheng, M.M.C., and Li, T. (2024). Fundamentals, Algorithms, and Technologies of Occupancy Detection for Smart Buildings Using IoT Sensors. Sensors, 24.","DOI":"10.3390\/s24072123"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Cano-Su\u00f1\u00e9n, E., Mart\u00ednez, I., Fern\u00e1ndez, \u00c1., Zalba, B., and Casas, R. (2023). Internet of Things (IoT) in Buildings: A Learning Factory. Sustainability, 15.","DOI":"10.20944\/preprints202306.2205.v1"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"113717","DOI":"10.1016\/j.enbuild.2023.113717","article-title":"Method of test for CO2-based demand control ventilation systems: Benchmarking the state-of-the-art and the undervalued potential of proportional-integral control","volume":"301","author":"Pistochini","year":"2023","journal-title":"Energy Build."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2499","DOI":"10.1016\/j.enbuild.2011.06.005","article-title":"A novel and dynamic demand-controlled ventilation strategy for CO2 control and energy saving in buildings","volume":"43","author":"Lu","year":"2011","journal-title":"Energy Build."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1234","DOI":"10.1016\/j.enbuild.2005.01.003","article-title":"Occupancy density and benefits of demand-controlled ventilation in Norwegian primary schools","volume":"37","author":"Mysen","year":"2005","journal-title":"Energy Build."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.egypro.2017.04.013","article-title":"Simulation of Occupancy and CO2-based Demand-controlled Mechanical Ventilation Strategies in an Office Room Using EnergyPlus","volume":"113","author":"Chenari","year":"2017","journal-title":"Energy Procedia"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1109\/TASE.2016.2619720","article-title":"Occupancy Detection via Environmental Sensing","volume":"15","author":"Jin","year":"2018","journal-title":"IEEE Trans. Autom. Sci. Eng."},{"key":"ref_19","unstructured":"Lin, X., and Lau, J. (2025, March 28). Applying Demand-Controlled Ventilation. ASHRAE January 2016. Available online: https:\/\/www.aircuity.com\/wp-content\/uploads\/Applying-Demand-Control-Ventilation-ASHRAE-Journal-Jan-2016.pdf."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1080\/23744731.2019.1620575","article-title":"Energy savings and ventilation performance from CO2-based demand controlled ventilation: Simulation results from ASHRAE RP-1747 (ASHRAE RP-1747)","volume":"26","author":"Li","year":"2020","journal-title":"Sci. Technol. Built Environ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/S0378-7788(98)00029-2","article-title":"Sensor-based demand-controlled ventilation: A review","volume":"29","author":"Fisk","year":"1998","journal-title":"Energy Build."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1016\/j.scs.2016.03.008","article-title":"Teaching and researching the indoor environment: From traditional experimental techniques towards web-enabled practices","volume":"26","author":"Pereira","year":"2016","journal-title":"Sustain. Cities Soc."},{"key":"ref_23","unstructured":"Charlesworth, P.S. (1988). Air Exchange Rate and Airtightness Measurement Techniques\u2014An Application Guide, Air Infiltration and Ventilation Centre. Available online: https:\/\/www.aivc.org\/resource\/ag-air-exchange-rate-and-airtightness-measurement-techniques-application-guide."},{"key":"ref_24","first-page":"39","article-title":"Simple and Cheap Air Change Rate Measurement Using CO2 Concentration Decays","volume":"1","author":"Foradini","year":"2002","journal-title":"Int. J. Vent."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1111\/j.1600-0668.2006.00459.x","article-title":"Indoor air quality in Michigan schools","volume":"17","author":"Godwin","year":"2007","journal-title":"Indoor Air"},{"key":"ref_26","first-page":"45","article-title":"Carbon Dioxide Levels and Ventilation Rates in Schools","volume":"1","author":"Coley","year":"2002","journal-title":"Int. J. Vent."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1617","DOI":"10.1016\/j.buildenv.2011.01.027","article-title":"Indoor air quality audit implementation in a hotel building in Portugal","volume":"46","author":"Asadi","year":"2011","journal-title":"Build. Environ."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"244","DOI":"10.1016\/j.enbuild.2012.09.005","article-title":"Energy intelligent buildings based on user activity: A survey","volume":"56","author":"Nguyen","year":"2013","journal-title":"Energy Build."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"3264","DOI":"10.1109\/TMC.2017.2684806","article-title":"Virtual Occupancy Sensing: Using Smart Meters to Indicate Your Presence","volume":"16","author":"Jin","year":"2017","journal-title":"IEEE Trans. Mob. Comput."},{"key":"ref_30","first-page":"307","article-title":"Experimental evaluation of CO2-based demand-controlled ventilation strategies","volume":"108","author":"Alalawi","year":"2002","journal-title":"ASHRAE Trans."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Otoo, C., Lu, T., and L\u00fc, X. (2024). Application of Mixed-Mode Ventilation to Enhance Indoor Air Quality and Energy Efficiency in School Buildings. Energies, 17.","DOI":"10.3390\/en17236097"}],"container-title":["Air"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2813-4168\/3\/2\/17\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:46:46Z","timestamp":1760032006000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2813-4168\/3\/2\/17"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,4]]},"references-count":31,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["air3020017"],"URL":"https:\/\/doi.org\/10.3390\/air3020017","relation":{},"ISSN":["2813-4168"],"issn-type":[{"value":"2813-4168","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,4]]}}}