CO2 Concentrations and Thermal Comfort Analysis at Onsite and Online Educational Environments

Int J Environ Res Public Health. 2022 Nov 30;19(23):16039. doi: 10.3390/ijerph192316039.


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' 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.

Keywords: COVID-19; IAQ; on-site education; online education; thermal comfort.

MeSH terms

  • Air Pollution, Indoor* / analysis
  • COVID-19*
  • Carbon Dioxide / analysis
  • Humans
  • SARS-CoV-2
  • Ventilation


  • Carbon Dioxide