The Transport of Gaseous Pollutants due to Stack Effect in High-Rise Residential Buildings

Nowadays, there is increasing construction of high-rise buildings. Stack effect is one of the airflow characteristics in this type of tall buildings. The upward buoyant airflows in vertical shafts of high-rise residential (HRR) buildings can become an important way of gaseous pollutant transport during cold seasons. In this paper the airflows and pollutant transport driven by stack effect in a typical HRR building in Shanghai was simulated by using a multi-zone model. Measured and recommended leakage data were employed, and the air tightness level was kept the same for all floors. It was found that the air change rate per hour (ac/h) was less than 0.5 under temperature differences (TDs) from 10°C to 30°C at a typical air tightness level when all windows and doors were fully closed. Two types of pollutant sources were investigated. The TD and source location have a great impact on the pollutant concentration. A lower source location would cause a higher concentration in the flats above the neutral plane level (NPL). The relationship of the TD and concentration above the NPL varied with the source type and time. The accumulating process of the pollutant could be easily interrupted by artificial measures such as opening windows. It is recommended to open windows at set intervals to strengthen short-term natural ventilation even during the cold seasons.