AOV Automatic Opening Ventilators for smoke ventilation in the event of fire
Smoke control using natural ventilation is a particularly effective means of protecting escaping occupants, those awaiting rescue and fire-fighters from the immediate dangers of fire and smoke.
In principle, high-level outlet vents and low-level inlet vents open automatically in the event of a fire to allow cool air into the building and allow smoke and hot air to flow out. This improves the conditions for occupants to escape and fire-fighters to enter. In the absence of ventilation, smoke fills the room, being drawn back down from the ceiling by convection as temperatures rise, leading to potential—and particularly dangerous—‘flashover’.
The specific design of an effective and safe smoke ventilation system requires specialist involvement, perhaps by the mechanical and electrical consultant, and may well form part of a fire engineering solution. In England and Wales, Part B of the Building Regulations covers fire and the Approved Document (AD B) Volume 2 provides guidance applicable to flats and non-dwellings. The following national, regulatory guidelines have similar requirements: Section 2 of the Scottish Building Standards Agency Technical Handbooks 2007; Technical Booklet E of the Building Regulations (Northern Ireland); Technical Guidance Document B of the Government of Ireland Building Regulations 2006. AD B identifies a number of situations where AOVs to provide natural ventilation are appropriate, including: Small single-stair blocks of flats Common escape routes in larger blocks of flats Basement areas Enclosed car parks Vertical smoke shafts, as part of a smoke control design In several cases, AD B specifies the minimum of ventilation—generally either 1 m2 or 1.5 m2.
NARM member companies can offer a variety of AOV options, from modular domes to structural glazing systems with integral AOV sections.
