Measurement and CFD modelling of airflow through stairwells.

The present paper deals with one of the most important mechanisms of inter-zone mass and energy transfer, namely the buoyancy-driven flows through stairwells that connect the floors of buildings. To further investigate these phenomena, experimental as well as theoretical studies have been carried out. A series of experiments have been performed in order to study the airflow through a typical stairwell that connects the two individual zones of a two-storey house. Airflow rates between the two zones were measured using a single tracer gas decay technique. The analysis of results provided relations which can predict the volumetric flow rate as a function of the interzonal average temperature difference between the two floors. Simulations of these experiments were carried out, using validated CFD algorithms. Airflow rates estimated by these simulations showed good agreement with experimental values despite the difficulties related to the applicability of CFD to model the buoyancy driven flows. Finally the paper discusses the airflow patterns through the stairwell.