In this paper, a new mathematical model was developed experimentally to quantify the air volume flow by natural ventilation through window tilt opening. The experiment was carried out with two test facades in a laboratory building in Aachen, Germany. The test facades are equipped with windows in two different dimensions, and they are located under real weather conditions. The modelling data were determined by means of more than 70 tracer gas measurements with CO2. The new model represents that the volume flow rate through the window opening can be estimated more reliably by the measured pressure difference between the outdoor and indoor air. The results will be used for a development of a hybrid ventilation control.
