Intervention study of climate correlation model predictions for occupant control of indoor environment

Occupants in natural ventilated buildings usually control ventilation through window opening. As part of the PRELUDE H2020 project a framework of how to predict an indoor environment by correlating internal environmental variables and external climatic variables was developed; this was presented at the AIVC conference in 2022. The climate correlation model consists of equations correlating external and internal parameters, derived from predictions of a thermal model (EnergyPlus) of the target building. Using these equations, thermal comfort (operative temperature) and IAQ (CO2 concentration) are calculated using short term (24hrs) forecasted external weather data (air temperature and wind speed) that informs for window opening actions by the occupants. The model was applied in three naturally ventilated buildings in Greece (hostel), Switzerland (apartment) and Poland (office). A climate correlation model was developed for each building and equations derived specifically for the building.  Occupant actions for opening windows were then determined for two consequent days in each of the buildings. The actions were communicated to the building occupants using conventional method (email); this was done through the building manager for the hostel and directly to occupants for the office and apartment. Data of internal temperature and CO2 concentration were measured, analysed and compared to the predictions of the climate correlation model. The tests were carried out successfully and the comparison of predictions (based on weather forecasts) and measurements in the building is quite good for IAQ (CO2) as the ventilation intervals are captured well. Thermal comfort was also captured well with some under prediction at night, because of differences in air flow rates due to different window opening areas and some divergence when windows were simulated open during cold days with heating off.  This study demonstrates that for low technology buildings where actuators and sensors are not present, a single thermal study and associated correlation equations for the building can effectively inform the occupants on the best way to control their internal environment based on prevailing external conditions.