An indoor air quality and thermal comfort appraisal in a retrofitted university building via low-cost smart sensor

Abstract

Occupant health can be strongly influenced by indoor air quality due to time spent indoors (90%). Such quality can be impacted by indoor atmospheric pollutants present. Therefore, demand-controlled ventilation can be a key to improving indoor air quality. The main aim herein is to scrutinize measurement results of several air pollutants possibly existing inside university building including CO₂, volatile organic compounds, formaldehyde, benzene, CO, PM_2.5 during three measurement campaigns (March 2017, May 2017 and October–November 2017) via a smart sensor specially developed. Likewise, some factors to assess comfort such as relative humidity and ambient air temperature were examined. CO₂ were found to be higher during periods of occupancy with concentrations exceeding 2000 ppm during the first campaign. As a result, the occupants felt uncomfortable. Analysis of the survey results regarding the indoor air temperature showed that 80% of occupants found the temperature during school periods to be uncomfortable. In addition, the ICONE air containment index was extremely high, indicating that the deemed class was confined during occupancy. The outcomes will be useful for the development of future indoor air quality guidelines, ventilation design and occupant satisfaction in buildings.