29.3 Ventilation controls for the fire service To ensure the effective use of ventilation systems or override controls provided for fire service use, it is essential that the provision, location and the mode of operation of such facilities are discussed and agreed with the fire service, the designer of the systems, the user of the premises and the building control authority before any decision to provide override facilities for either fire safety or normal air handling systems. The location of the controls and their functions should be clearly marked in accordance with Table 6, and the signage should be in accordance with BS 5499-1 Table 6 — Location and signing of ventilation controls for fire service use Ventilation system
Atrium ventilation (temperature control system)
Location of control panel
Fire control centre or adjacent to fire alarm panel if fire control centre is not required
Smoke exhaust ventilation system Fire control centre
HVAC incorporating smoke exhaust ventilation system
Adjacent to fire alarm panel
Facilities and marking
“FIRE SERVICE VENTILATION CONTROL” “Atrium Emergency Ventilation Control” “Automatic” “Off” “Extract only” “FIRE SERVICE VENTILATION CONTROL” “Automatic” “Off” “Extract only” “FIRE SERVICE VENTILATION CONTROL” “Automatic” “Off” “Extract only”
Where the systems are relatively simple and the areas covered by these systems can be readily seen, manual control can be exercised to make the best use of the systems according to the extent of the fire and amount of smoke present. This enables the fire service to better deploy their resources to suppress the fire, minimize smoke damage and finally remove residual smoke when the fire is suppressed. Firefighting controls should be provided to enable: a) normal ventilation systems to be switched off or to be operated only on full exhaust to outside the building with the dampers in recirculation air ducts closed; b) powered smoke exhaust ventilation systems to be operated fully on or to be switched off; c) natural smoke ventilators to operate fully to open position. NOTE 1
The provisions of indicator lamps at the controls’ positions showing clearly the mode of operation of the controls is useful.
A warning sound and visual indicator should be given at the control position when the firefighting control of any smoke control system is in the isolated condition. NOTE 2
The warning indicator should be maintained until the systems are restored and fully functionable.
The controls should be accessible without the use of a key but protected to prevent operation by unauthorized persons, e.g. located in an enclosure with a front made of transparent frangible material. The purpose and operating positions of the control(s) should be clearly indicated with permanent marking or labels. Where the arrangement of the ventilation system is not immediately apparent, a suitable schematic diagram should be provided at the control’s position, indicating the locations of all the ventilation fans/ventilators controlled by the firefighting controls. Any arrangement for the interconnection of the ventilation controls with a central processing system should be such that any fault developing on the system or any change from its normal operation (including when it is being maintained) will not jeopardize the operation of the firefighting controls.
© BSI 8 December 2004