Impact of Floor Planning on Airflow Patterns in Designated Refuge Floor in High-Rise Building

Abstract

Refuge floorspace is implemented as a temporary place for high-rise-building evacuees to take a short rest before further evacuating in the case of a fire. It is specified as a requirement in the Fire Code of Hong Kong to provide designated refuge floors for high-rise buildings. To meet its desired function, a refuge floor must be a safe place for evacuees. However, the safety of refuge floors under fire situations may be impaired if the floor is affected by smoke ingress from other levels. The code prescribes that cross-ventilation should be provided in refuge floors so as to prevent smoke accumulation. Even with sufficient cross-ventilation, the prevention and/or extraction of smoke in the refuge floor cannot be guaranteed. In fact, the airflow pattern and smoke extraction/dilution largely depend on the floor planning in designated refuge floorspace. A study of the impact of refuge floor settings on the airflow around and inside the refuge floor is required and expected to provide some insight on the smoke movement pattern. In this paper, the computational fluid dynamics method is employed to predict and analyze the air movement around and inside a designated refuge floor within a high-rise building under different floor-plans. The study shows that the floor-plan does affect airflow patterns and further the potential smoke dispersion in the refuge floor.