CALCULATION OF SMOKE VENTILATION IN BUILDING FIRES INCLUDING ATRIUMS

M J Kauriala

1999

 

ABSTRACT

Large quantities of smoke, heat and toxic gases are produced in a building fire. Due to air entrainment into the fire plume, an increasing volume of smoke is generated and spreads throughout the upper layer. The smoke forms a layer which deepens, filling the compartment while simultaneously reducing the visibility, risking the egress safety of the occupants and endangering the operative action of the fire brigade. Furthermore, the structural safety, the property and the personal estate are also endangered by the heat and smoke. For these reasons, the movement of heat and smoke should be effectively removed from the compartment. For the design of buildings, a reliable method of smoke ventilation is the single most important instrument.

Nowadays, the design of novel types of atrium in new buildings is very popular, thus the aim of the current research work is to evaluate methodologies that define guidelines as to the design of smoke ventilation systems in such large spaces.

The research work consisted of a survey analysis of three different calculation methods and the application of these methods in real atrium space.

The literature survey consisted of the basic principles of smoke production, fire development, smoke ventilation theory, fire zone modelling in closed and open rooms, building codes and numerical simulation models of smoke ventilation.

For the analysis three methods were chosen (1) the Finnish Building Regulations "Clarification 7", (2) NFPA 92B and (3) Argos Fire Zone Modelling Programme.

Calculations were carried out using the above mentioned codes. The results indicate that all methods are reliable. However, the study points out that a fire zone modelling simulation programme is a very suitable tool to design atrium smoke ventilation systems. It is quick to use and it gives more relevant information than other methods used in the current.