Buoyancy-driven natural ventilation in a thermally stratified one-zone building

Abstract Airflow and thermal stratification solutions in a single-zone building with buoyancy-driven ventilation are derived. Two new ‘empty air-filling box’ models are developed, and it is shown that the fully-mixed model overpredicts the clean zone height and the ventilation airflow rate, while the ‘emptying water-filling box’ model underpredicts the two ventilation parameters. It is also found that the fully mixed model predicts a much lower neutral level height for the building than that predicted by models considering thermal stratification.