In the case of a fire within a building, more than 90% of fatalities are caused by smoke poisoning. Smoke ventilation devices allow for the life-threatening smoke to be released into the open or to dilute its concentration. The danger is therefore reduced before smoke spreads through a building and escape routes like halls and staircases become impassable.
Upon smoke detection, the vents will be automatically opened by electric motor drives. Automatic Opening Vents (AOV) are located in positions specified in BS5588. Rising smoke, toxic gases and heat is drawn off into the open through the smoke vents so that escape and rescue routes remain passable. To achieve the effect of rising thermal current it is often necessary to provide fresh air openings in the lower part of the building. Usually it is necessary to provide automatic opening vents at the top of escape stairwells and lobbies which constitute escape routes.
ECS specialise in fitting automatic opening actuators and devices to windows, roof windows or doors.
These devices will be linked to a central control panel, complete with a battery backup system in case of mains failure. The smoke vent system can be operated by manual override break glass switches on the ground floor, by dedicated smoke detectors or by interfacing with a third party smoke detection/fire alarm system. A smoke ventilation system can be also used for daily natural ventilation.
Fig 1 below shows how rising smoke, heat and toxic gases are drawn out of the building creating a clear escape route.
