Time-dependent occupant behaviour models of window control in summer

This study aims to extend the understanding of the window-opening control by occupants in private and two-person offices in summer. A field study was carried out from 13 June to 15 September 2006 in offices with and without night ventilation, located in Cambridge, UK. The monitoring data give evidence that there is a statistically significant relationship between window-opening behaviour patterns and indoor stimulus (i.e., indoor air temperature) in summer. The activity of window control in offices both with and without night ventilation was mostly constrained to the start of period of occupation. Once a window state had been set up on the arrival it mainly stayed the same until departure. The percentages of total window change events in offices without night ventilation during the intermittent period from open to closed and closed to open were 3% and 2%, respectively. A window in an office that featured a night cooling strategy was always open upon the departure whenever the room temperature was over 23.6 °C. Finally, the stochastic models to predict window-opening behaviour patterns as a function of indoor temperature, time of day and the previous window state were developed.