{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,28]],"date-time":"2026-06-28T16:17:42Z","timestamp":1782663462251,"version":"3.54.5"},"reference-count":52,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2022,11,30]],"date-time":"2022-11-30T00:00:00Z","timestamp":1669766400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003030","name":"L\u2019Ag\u00e8ncia de Gesti\u00f3 d\u2019Ajuts Universitaris i de Recerca (AGAUR)","doi-asserted-by":"publisher","award":["2020PANDE00116"],"award-info":[{"award-number":["2020PANDE00116"]}],"id":[{"id":"10.13039\/501100003030","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003030","name":"L\u2019Ag\u00e8ncia de Gesti\u00f3 d\u2019Ajuts Universitaris i de Recerca (AGAUR)","doi-asserted-by":"publisher","award":["2017 SGR 227"],"award-info":[{"award-number":["2017 SGR 227"]}],"id":[{"id":"10.13039\/501100003030","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003030","name":"L\u2019Ag\u00e8ncia de Gesti\u00f3 d\u2019Ajuts Universitaris i de Recerca (AGAUR)","doi-asserted-by":"publisher","award":["2017 SGR 814"],"award-info":[{"award-number":["2017 SGR 814"]}],"id":[{"id":"10.13039\/501100003030","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003030","name":"L\u2019Ag\u00e8ncia de Gesti\u00f3 d\u2019Ajuts Universitaris i de Recerca (AGAUR)","doi-asserted-by":"publisher","award":["2017 SGR 1219"],"award-info":[{"award-number":["2017 SGR 1219"]}],"id":[{"id":"10.13039\/501100003030","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Catalan agency AGAUR","award":["2020PANDE00116"],"award-info":[{"award-number":["2020PANDE00116"]}]},{"name":"Catalan agency AGAUR","award":["2017 SGR 227"],"award-info":[{"award-number":["2017 SGR 227"]}]},{"name":"Catalan agency AGAUR","award":["2017 SGR 814"],"award-info":[{"award-number":["2017 SGR 814"]}]},{"name":"Catalan agency AGAUR","award":["2017 SGR 1219"],"award-info":[{"award-number":["2017 SGR 1219"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>In building areas with high occupancy, such as classrooms, transmission routes of SARS-CoV-2 are increased when indoor air quality is deficient. Under this scenario, universities have adopted ventilation measures to mitigate contagious environments. However, the lack of adequate equipment or designs in old educational buildings is a barrier to reach minimum requirements. This study aims to quantify the indoor air quality and thermal comfort at universities and compare it to conditions in students\u2019 households. In this regard, several classrooms in buildings of the Polytechnic University of Catalonia were monitored for temperature, CO2 concentration and relative humidity. The people who used these classrooms were surveyed about their comfort perceptions. A sample of students was also monitored at their homes where they reported to studying during the exam period. By means of point-in-time surveys, students reported their daily comfort, for comparison with the monitored data. The results show that the recommendations for CO2 concentration, temperature, and relative humidity are not always met in any of the study spaces. These factors are more critical at universities due to the high occupancy. In addition, the surveys highlighted the perception that the environment is better at home than at university.<\/jats:p>","DOI":"10.3390\/ijerph192316039","type":"journal-article","created":{"date-parts":[[2022,12,1]],"date-time":"2022-12-01T01:54:31Z","timestamp":1669859671000},"page":"16039","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":22,"title":["CO2 Concentrations and Thermal Comfort Analysis at Onsite and Online Educational Environments"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7149-6873","authenticated-orcid":false,"given":"Alba","family":"Alegr\u00eda-Sala","sequence":"first","affiliation":[{"name":"Enginyeria del Medi Ambient (ENMA), Department of Project and Construction Engineering (DPCE), Universitat Polit\u00e8cnica de Catalunya (UPC), 08028 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9290-4469","authenticated-orcid":false,"given":"Elisenda","family":"Cl\u00e8ries Tard\u00edo","sequence":"additional","affiliation":[{"name":"Thermal Energy and Building Performance Group, Catalonia Institute for Energy Research (IREC), 08930 Catalonia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4791-9917","authenticated-orcid":false,"given":"Lluc Canals","family":"Casals","sequence":"additional","affiliation":[{"name":"Enginyeria del Medi Ambient (ENMA), Department of Project and Construction Engineering (DPCE), Universitat Polit\u00e8cnica de Catalunya (UPC), 08028 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5469-7291","authenticated-orcid":false,"given":"Marcel","family":"Macarulla","sequence":"additional","affiliation":[{"name":"Group of Construction Research and Innovation (GRIC), Department of Project and Construction Engineering (DPCE), Universitat Polit\u00e8cnica de Catalunya (UPC), 08222 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7035-3248","authenticated-orcid":false,"given":"Jaume","family":"Salom","sequence":"additional","affiliation":[{"name":"Thermal Energy and Building Performance Group, Catalonia Institute for Energy Research (IREC), 08930 Catalonia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,11,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Adhanom Ghebreyesus, T. (2020). Virtual Press Conference on COVID-19.","DOI":"10.1002\/wps.20768"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1111\/irv.12735","article-title":"Uncertainties about the Transmission Routes of 2019 Novel Coronavirus","volume":"14","author":"Han","year":"2020","journal-title":"Influenza Other Respir. Viruses"},{"key":"ref_3","first-page":"702066","article-title":"Original Hosts, Clinical Features, Transmission Routes, and Vaccine Development for Coronavirus Disease (COVID-19)","volume":"1","author":"Kiani","year":"2019","journal-title":"Front. Med."},{"key":"ref_4","unstructured":"(2022, May 23). UPC Instrucci\u00f3n del Rector Relativa a la Adaptaci\u00f3n del Plan de Contingencia de la UPC a la Propuesta de Plan Sectorial de Universidades del PROCICAT. Curso 2021\u20132022. Available online: https:\/\/www.upc.edu\/es\/sala-de-prensa\/pdf\/instruccion_rector_plan_contingencia_COVID_curso2021_22_es.pdf."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"422","DOI":"10.1111\/ina.12639","article-title":"Effect of Ventilation Improvement during a Tuberculosis Outbreak in Underventilated University Buildings","volume":"30","author":"Du","year":"2019","journal-title":"Indoor Air"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"107368","DOI":"10.1016\/j.buildenv.2020.107368","article-title":"Review and Comparison of HVAC Operation Guidelines in Different Countries during the COVID-19 Pandemic","volume":"187","author":"Guo","year":"2021","journal-title":"Build. Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"751","DOI":"10.5094\/APR.2015.084","article-title":"A Review of Standards and Guidelines Set by International Bodies for the Parameters of Indoor Air Quality","volume":"6","author":"En","year":"2015","journal-title":"Atmos. Pollut. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1111\/j.1600-0668.1999.00003.x","article-title":"Association of Ventilation Rates and CO2 Concentrations with Health and Other Responses in Commercial and Institutional Buildings","volume":"9","author":"Fisk","year":"1999","journal-title":"Indoor Air"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"392","DOI":"10.1021\/acs.estlett.1c00183","article-title":"Exhaled CO2 as a COVID-19 Infection Risk Proxy for Different Indoor Environments and Activities","volume":"8","author":"Peng","year":"2021","journal-title":"Cite This Environ. Sci. Technol. Lett."},{"key":"ref_10","unstructured":"Ministerio de Sanidad (2022, May 23). Recomendaciones de Operaci\u00f3n y Mantenimiento de los Sistemas de Climatizaci\u00f3n y Ventilaci\u00f3n de Edificios y Locales para la Prevenci\u00f3n de la Propagaci\u00f3n del SARS-CoV-2. Available online: https:\/\/www.mscbs.gob.es\/profesionales\/saludPublica\/ccayes\/alertasActual\/nCov\/documentos\/Recomendaciones_de_operacion_y_mantenimiento.pdf."},{"key":"ref_11","unstructured":"MITES (2022, May 23). INSST La Ventilaci\u00f3n Como Medida Preventiva Frente Al Coronavirus SARS-CoV-2. Available online: https:\/\/www.insst.es\/documents\/94886\/712877\/La+ventilaci%C3%B3n+como+medida+preventiva+frente+al+coronavirus+SARS-CoV-2.pdf\/7d80e9f3-2b44-7e37-8af2-7ab105621070?t=1626298548369#:~:text=Considerando%20esta%20v%C3%ADa%20de%20transmisi%C3%B3n,(OMS)%20%5B1%5D."},{"key":"ref_12","unstructured":"(2022, May 23). Ministerio de Salud Documento T\u00e9cnico: Evaluaci\u00f3n Del Riesgo de La Transmisi\u00f3n de SARS-CoV-2 Mediante Aerosoles. Medidas de Prevenci\u00f3n y Recomendaciones. Available online: https:\/\/www.sanidad.gob.es\/profesionales\/saludPublica\/ccayes\/alertasActual\/nCov\/documentos\/COVID19_Aerosoles.pdf."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"L\u00f3pez, A., Fuentes, E., Yus\u00e0, V., Xavier L\u00f3pez-Labrador, F., Camar\u00f3, M., Peris-Martinez, C., Ll\u00e1cer, M., Ortol\u00e1, S., Coscoll\u00e0, C., and Delhomme, O. (2021). Indoor Air Quality Including Respiratory Viruse. FISABIO Mediterr. Ophthalmol. Found., 12.","DOI":"10.3390\/toxics9110274"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"111560","DOI":"10.1016\/j.envres.2021.111560","article-title":"CO2 Concentration Monitoring inside Educational Buildings as a Strategic Tool to Reduce the Risk of SARS-CoV-2 Airborne Transmission","volume":"202","author":"Palmisani","year":"2021","journal-title":"Environ. Res."},{"key":"ref_15","unstructured":"(2019). Energy Performance of Buildings. Ventilation for Buildings Indoor Environmental Input Parameters for Design and Assessment of Energy Performance of Buildings Addressing Indoor Air Quality. Thermal Environment, Lighting and Acoustics. Module M1-6. Standard No. BS EN 16798-1:2019. Available online: https:\/\/standards.iteh.ai\/catalog\/standards\/cen\/b4f68755-2204-4796-854a-56643dfcfe89\/en-16798-1-2019."},{"key":"ref_16","first-page":"1405","article-title":"Comparative Study of Clinical Symptoms, Laboratory Results and Imaging Features of Coronavirus and Influenza Virus, Including Similarities and Differences of Their Pathogenesis","volume":"14","author":"Karimian","year":"2020","journal-title":"Pak. J. Med Health Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1016\/j.jinf.2008.08.013","article-title":"Inactivation of Influenza A Viruses in the Environment and Modes of Transmission: A Critical Review","volume":"57","author":"Weber","year":"2008","journal-title":"J. Infect."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"5650","DOI":"10.1128\/JVI.00325-08","article-title":"High Temperature (30 \u00b0C) Blocks Aerosol but Not Contact Transmission of Influenza Virus","volume":"82","author":"Lowen","year":"2008","journal-title":"J. Virol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Lowen, A.C., Mubareka, S., Steel, J., and Palese, P. (2007). Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature. Plos Pathog., 3.","DOI":"10.1371\/journal.ppat.0030151"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1080\/17512549.2015.1014845","article-title":"Thermal Discomfort and Health: Protecting the Susceptible from Excess Cold and Excess Heat in Housing","volume":"10","author":"Ormandy","year":"2015","journal-title":"Adv. Build. Energy Res."},{"key":"ref_21","first-page":"9","article-title":"Indoor Temperature and Health: A Global Systematic Review","volume":"9","author":"Tham","year":"2019","journal-title":"Public Health"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"111831","DOI":"10.1016\/j.enbuild.2022.111831","article-title":"A Critical Review on Occupant Behaviour Modelling for Building Performance Simulation of Naturally Ventilated School Buildings and Potential Changes Due to the COVID-19 Pandemic","volume":"258","author":"Franceschini","year":"2022","journal-title":"Energy Build."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1671","DOI":"10.1289\/ehp.1104789","article-title":"Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making Performance","volume":"120","author":"Satish","year":"2012","journal-title":"Environ. Health Perspect."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1067","DOI":"10.1111\/ina.12706","article-title":"Indoor CO2 Concentrations and Cognitive Function: A Critical Review","volume":"30","author":"Du","year":"2020","journal-title":"Indoor Air"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.apergo.2010.04.003","article-title":"The Effects of Air Temperature on Office Workers\u2019 Well-Being, Workload and Productivity-Evaluated with Subjective Ratings","volume":"42","author":"Lan","year":"2010","journal-title":"Appl. Ergon."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1016\/j.buildenv.2013.06.012","article-title":"Influence of Indoor Air Temperature on Human Thermal Comfort, Motivation and Performance","volume":"68","author":"Cui","year":"2013","journal-title":"Build. Environ."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2845","DOI":"10.1002\/jmv.27661","article-title":"Novel Statistics Predict the COVID-19 Pandemic Could Terminate in 2022","volume":"94","author":"Chen","year":"2022","journal-title":"J. Med. Virol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"11850","DOI":"10.1021\/acs.jpclett.1c03380","article-title":"Mechanisms of SARS-CoV-2 Evolution Revealing Vaccine-Resistant Mutations in Europe and America","volume":"12","author":"Wang","year":"2021","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"869","DOI":"10.1038\/s41558-022-01426-1","article-title":"Over Half of Known Human Pathogenic Diseases Can Be Aggravated by Climate Change","volume":"12","author":"Mora","year":"2022","journal-title":"Nat. Clim. Chang."},{"key":"ref_30","first-page":"353","article-title":"A Review of CO2 Measurement Procedures in Ventilation Research","volume":"10","author":"Mahyuddin","year":"2012","journal-title":"Int. J. Vent."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3021","DOI":"10.21105\/joss.03021","article-title":"Seaborn: Statistical Data Visualization","volume":"6","author":"Waskom","year":"2021","journal-title":"J. Open Source Softw."},{"key":"ref_32","unstructured":"(2022, May 23). Global Monitoring Laboratory\u2014Carbon Cycle Greenhouse Gases, Available online: https:\/\/gml.noaa.gov\/ccgg\/trends\/gl_data.html."},{"key":"ref_33","unstructured":"(1997). MITES Real Decreto 486\/1997, de 14 de Abril, Por El Que Se Establecen Las Disposiciones M\u00ednimas de Seguridad y Salud En Los Lugares de Trabajo. Boe, 97, 12918\u201312926."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1353","DOI":"10.1016\/j.rser.2017.05.175","article-title":"A Review of Thermal Comfort Models and Indicators for Indoor Environments","volume":"79","author":"Enescu","year":"2017","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_35","first-page":"313","article-title":"Assessment of Man\u2019s Thermal Comfort in Practice","volume":"30","author":"Fanger","year":"1973","journal-title":"Br. J. Ind. Med."},{"key":"ref_36","first-page":"106","article-title":"Thermal Comfort and Its Importance for the Architectural Design and Environmental Quality of Indoors Spaces","volume":"7","author":"Jara","year":"2015","journal-title":"Arquit. Cult."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1111\/j.1600-0668.2004.00268.x","article-title":"International Standards for the Indoor Environment","volume":"14","author":"Olesen","year":"2004","journal-title":"Indoor Air Suppl."},{"key":"ref_38","first-page":"145","article-title":"Developing an Adaptive Model of Thermal Comfort and Preference","volume":"104","author":"Brager","year":"1997","journal-title":"ASHRAE Trans."},{"key":"ref_39","unstructured":"(2020). Thermal Environmental Conditions for Human Occupancy. Standard No. ASHRAE ANSI\/ASHRAE 55-2020."},{"key":"ref_40","unstructured":"(2022, May 23). API de Dades Meteorol\u00f2giques\u2014API REST de Dades Meteorol\u00f2giques. Available online: https:\/\/apidocs.meteocat.gencat.cat\/documentacio\/."},{"key":"ref_41","unstructured":"(2017). Thermal Enviromental Conditions for Human Occupancy. Standard No. ASHRAE ANSI\/ASHRAE Standard 55-2017."},{"key":"ref_42","unstructured":"Catalunya, S.M. (2022, May 23). De Butllet\u00ed Clim\u00e0tic Mensual Juny del 2022. Available online: https:\/\/static-m.meteo.cat\/wordpressweb\/wp-content\/uploads\/2022\/07\/21085939\/Butlleti-Juny2022.pdf."},{"key":"ref_43","unstructured":"De Santiago, E. (2022, May 23). (01) Segmentaci\u00f3n del Parque Residencial de Viviendas en Espa\u00f1a en Cl\u00fasteres Tipol\u00f3gicos. Available online: https:\/\/cdn.mitma.gob.es\/portal-web-drupal\/planes_estartegicos\/1_2020_segmentacion_parque_residencial_clusteres.pdf."},{"key":"ref_44","unstructured":"PROYECTO SECH-SPAHOUSEC (2011). An\u00e1lisis del Consumo Energ\u00e9tico del Sector Residencial en Espa\u00f1a, Instituto para la Diversificaci\u00f3n y Ahorro de Energ\u00eda; IDEA. Available online: https:\/\/www.idae.es\/uploads\/documentos\/documentos_Informe_SPAHOUSEC_ACC_f68291a3.pdf."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"108215","DOI":"10.1016\/j.buildenv.2021.108215","article-title":"Is Mixed-Mode Ventilation a Comfortable Low-Energy Solution? A Literature Review","volume":"205","author":"Kim","year":"2021","journal-title":"Build. Environ."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1016\/j.enbuild.2019.02.002","article-title":"Towards the Quantification of Energy Demand and Consumption through the Adaptive Comfort Approach in Mixed Mode Office Buildings Considering Climate Change","volume":"187","year":"2019","journal-title":"Energy Build."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Rodriguez, C., Coronado, M., D\u2019Alessandro, M., and Medina, J. (2019). The Importance of Standardised Data-Collection Methods in the Improvement of Thermal Comfort Assessment Models for Developing Countries in the Tropics. Sustainability, 11.","DOI":"10.3390\/su11154180"},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Ortiz, J., Jim\u00e9nez Mart\u00ednez, M., Alegr\u00eda-Sala, A., Tirado-Herrero, S., Gonz\u00e1lez Pijuan, I., Guiteras Blaya, M., and Canals Casals, L. (2021). Tackling Energy Poverty through Collective Advisory Assemblies and Electricity and Comfort Monitoring Campaigns. Sustainability, 13.","DOI":"10.3390\/su13179671"},{"key":"ref_49","unstructured":"Seppanen, O., Fisk, W.J., and Lei, Q.H. (2006, January 21\u201324). Effect of Temperature on Task Performance in Office Environment. Proceedings of the 5th International Conference on Cold Climate Heating, Ventilating and Air Conditioning, Moscow, Russia."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1016\/j.buildenv.2017.05.022","article-title":"The Impact of Thermal Environment on Occupant IEQ Perception and Productivity","volume":"121","author":"Geng","year":"2017","journal-title":"Build. Environ."},{"key":"ref_51","unstructured":"Canals Casals, L., Amante Garc\u00eda, B., Macarulla, M., L\u00f3pez-Grimau, V., and Guinart, A. (2021, January 7\u20139). The Adaptation of Project Management Courses into Virtual Teaching Due to COVID-19. Proceedings of the 25th International Congress on Project Management and Engineering, Alcoy, Spain."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Altindag, D.T., Filiz, E.S., and Tekin, E. (2021). Is Online Education Working?, National Bureau of Economic Research.","DOI":"10.3386\/w29113"}],"container-title":["International Journal of Environmental Research and Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-4601\/19\/23\/16039\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:30:42Z","timestamp":1760146242000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-4601\/19\/23\/16039"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11,30]]},"references-count":52,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["ijerph192316039"],"URL":"https:\/\/doi.org\/10.3390\/ijerph192316039","relation":{},"ISSN":["1660-4601"],"issn-type":[{"value":"1660-4601","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,11,30]]}}}