single-sided ventilation

Even in Northern European climates, overheating in many Nearly Zero Energy Buildings is a barrier to year round occupant satisfaction with the indoor thermal environment. Improved energy performance and enhanced thermal comfort should not be perceived as a rigid dichotomy of concepts. However, an acceptable thermal environment, during extended cooling periods now present in NZEB’s, can come at a high energy cost if mechanical cooling is used.

Previous studies on single-sided natural ventilation are mostly limited to very simple physical models, such as a single-room or single-storey building. Our recent on-site measurements have shown that previous empirical models based on such simple physical models are inapplicable to multi-storey buildings. In order to explore why, this study systematically compares the ventilation characteristics of single-storey and multi-storey buildings with single-sided natural ventilation.

The aim was to develop a simple dynamic model for predicting air exchange caused by short time single-sided ventilation and necessary window opening time in classrooms. Tracer gas measurements have been made in a full-scale room. The comparison indicates that the model can be used when rough estimates of air exchange are of interest.