Influence of Indoor Air Pollutants, Temperature, Relative Humidity and Building-Related Factors on Perceived Air Quality (PAQ) in Office Buildings: Evidence from a Field Study

As the climate changes, it is crucial to understand how indoor contaminants, rising temperatures, and fluctuating relative humidity (RH) — all influenced by global warming — affect perceived air quality (PAQ). Additionally, analyzing the impact of building-related factors (e.g., orientation, floor level) on PAQ is particularly important in office buildings where occupants often lack control over ventilation and shading systems. This research investigates the relationship between environmental factors, building-related factors, and PAQ in office settings. A field study was conducted in an office building in Bolzano (northern Italy). Carbon dioxide (CO2), particulate matter (PM1, PM2.5, PM10), total volatile organic compounds (TVOC), air temperature, and RH were continuously monitored for a 5-week period during winter 2023. PAQ was assessed through a "right-here right-now" questionnaire using a 7-point Likert scale (from ―very dissatisfied‖ to ―very satisfied‖). Fifty-five individuals participated voluntarily, and their subjective feedback was correlated with thermal and indoor air quality (IAQ) parameters and building-related factors using a multiple linear regression analysis. Results showed that low RH values are associated with greater dissatisfaction with PAQ, while lower temperature values are linked to higher satisfaction with PAQ. Among the air contaminants, PM10 and PM2.5 have statistically significant effects, with higher levels associated with lower satisfaction ratings. Orientation and office facing also influence PAQ satisfaction, with an outdoor view being more favorable than an indoor courtyard view, and a west orientation being the least favorable. The study demonstrates complex relationships between these predictors, their interactions, and PAQ satisfaction.