Exploring the relationship between window operation behavior and thermal and air quality factors: A case study of UK residential buildings

Occupants' window operations can exert a substantial influence on the indoor environment. Although many researchers have studied the relationship between this adaptive behaviour and various types of environmental variables, certain types of pollutants such as indoor particulate matter (PM) and volatile organic compounds (VOC) remain poorly investigated. A field study was conducted in seventeen newly-built low-energy apartments in the UK to collect data on window status and a range of indoor and outdoor environmental variables including temperature, relative humidity, CO2, PM2.5 and TVOCs. The indoor monitoring for each apartment varied between six months and nearly one year across free-running and heating periods, with about half of the apartments having a few months' monitoring during the pandemic lockdown period. A series of logistic regression models were developed for each monitored window of the living room in these apartments, aimed at identifying the key driving factors for window opening and closing behaviour. Results of statistical significance tests suggested that indoor temperature was the most important influencing factor for window opening and closing behaviours. In contrast, none of the studied air quality variables was found to have a large impact on people's operations of windows.