NATURALLY vented smoke shaft systems (commonly known as AOV systems) in residential buildings should comply fully with the requirements of Approved Document B.
The dangers of having non-compliant systems was highlighted recently when a fire occurred in a block of flats where the smoke ventilation system was not configured to operate within these parameters, resulting in the fire spreading through the building via the ventilation shaft preventing the safe evacuation of occupants and compromising the safety of the emergency services.
To ensure correct operation of the smoke ventilation system the building owner must ensure the following:
• All flats should be fitted with working smoke detection
• Working door closes must be fitted to a fire rated door leading from the flat onto the corridor
• Upon sensing smoke, the AOV on the corridor leading from the flats should activate and open the vent into the smoke shaft
• The head of stair vent and the head of shaft vent should open simultaneously
• All other floors should “lock out” meaning that the operation of a smoke detector or override switch on other floors is ignored and all vents are kept closed to prevent smoke entering other floors through the open shaft
• The system must be regularly tested by a competent person to confirm the system is operating correctly. The testing regime should be as per the recommendations in BS: 9999.
SCS Support is the service and maintenance division of SCS Group, providing aftercare and ensuring that buildings stay safe after handover.
Our fire safety expertise means we are uniquely placed to guarantee projects are compliant with all building regulations and that building users are fully protected in the event of a fire.