Window-opening behavior in Chinese residential buildings across different climate zones

Window-opening behavior significantly influences indoor air quality (IAQ), energy consumption, and thermal comfort in residential buildings with natural ventilation. To understand window-opening behavior in Chinese residential buildings, this study conducted a one-year measurement in 58 apartments in 14 cities across five different climate zones in China. The influences of climate region, season, household type, and weekday/weekend pattern on the interaction between occupants and windows were analyzed and presented. The average daily “open-window” duration in Chinese bedrooms was 9.4 h. Generally, the length of time that the windows were open in cold regions was shorter than that in warm regions, even when the outdoor air temperatures among regions were similar. The open-window duration increased from winter to summer, as the outdoor air temperature increased. However, the duration decreased when the mean daily outdoor air temperature reached around 27 °C. Approximately 40% of the window-opening actions occurred in the morning from 6:00 to 9:00. During working hours (9:00-17:00) on weekdays, windows were opened more frequently if non-working persons were in the house. On weekends, residents opened windows at a later time than on weekdays. On the basis of the acquired information, a typical window-operation schedule as occupant behavior was proposed for Chinese bedrooms. It provides a more accurate boundary condition for analyses of IAQ, energy consumption, and thermal comfort in Chinese residential buildings.