Author(s)

L. Santarpia, F. Gugliermetti & G. Zori

Abstract

Thermal gradients, wind pressure and mechanical ventilation systems determine a natural airflow travelling the two atmospheres. A fire ignition in a confined space increases thermal gradients and determines a growing smoke flux towards adjacent atmospheres. A free air jet from an air curtain system reduces the exchange airflow and improves fire and smoke compartimentation. Two theoretical analyses are used for the air curtain device dimensioning in emergency conditions. The results provide guidelines to improve the project quality. Keywords: air curtain, confined fire, smoke control, ventilation device. 1 Introduction Smoke management methods can modify smoke movement to protect occupants and fire fighters, and to reduce property damage. Barriers and smoke vents, supplying and exhausting big air quantities (purging dilution) of air in fire space, are traditionally used. Doors coupled with mechanical fans are a very common system in smoke control, while as the single smoke purging is unable to provided the needed air flow attracted through the open door by pressure differences. In many practical applications escape routes towards refuge areas are not equipped with doors, especially in large common-space. In this case the use of air curtains, with the barrier function, could be useful reducing or delaying smoke infiltration towards escape ways. Atria in commercial multi-stories buildings, exhibition halls, sports arenas, railway stations are typical examples of large commonplaces where is suggested to apply an air curtain system. There are a lot of works and guidelines (NFPA 1995 [1], Klote and Milke 1992 [2], Tamura 1995 [3], Yamana and Tanaka 1985 [4], Hansell and Morgan 1994 [5]), standards and codes devoted to the design of smoke controls, but few papers regards on air curtain system used as a smoke barriers. Preliminary

Keywords

air curtain, confined fire, smoke control, ventilation device.