Investigation of Indoor Air Quality in Residential Buildings by Measuring CO2 Concentration and a Questionnaire Survey

Sensors (Basel). 2022 Sep 27;22(19):7331. doi: 10.3390/s22197331.


Indoor air quality (IAQ) in houses is often deteriorated by chemical substances emitted from heating, building materials, or other household goods. Since it is difficult for occupants to recognize air pollution, they rarely understand the actual conditions of the IAQ. An investigation into the actual condition of IAQ in houses was therefore conducted in this study. Carbon dioxide (CO2) concentrations in 24 occupied houses was measured, and the results from our analysis showed that the use of combustion heaters increased the concentration of CO2 and led to indoor air pollution. Results indicate that as outdoor temperature decreased, the frequency of ventilation decreased simultaneously, and CO2 concentration increased. Results of the questionnaire survey revealed that the actual IAQ in each house did not match the level of awareness its occupants had regarding ventilation. Along with this difficulty in perceiving air pollution, the lack of knowledge about ventilation systems and the effects of combustion heating may be additional barriers to IAQ awareness.

Keywords: CO2 concentration; in-home sensing; indoor air quality; ventilation.

MeSH terms

  • Air Pollutants* / analysis
  • Air Pollution, Indoor* / analysis
  • Carbon Dioxide / analysis
  • Environmental Monitoring / methods
  • Household Articles*
  • Surveys and Questionnaires
  • Ventilation


  • Air Pollutants
  • Carbon Dioxide

Grants and funding

This research received no external funding.