Pressurisation ductwork systems
Pressurisation ductwork is the ductwork used as part of a pressurisation system. Typically used in protected stairways, lobbies, corridors and fire fighting shafts, a pressurisation system is a special form of mechanical ventilation which maintains a positive pressure in critical areas to prevent smoke entering from adjacent areas.
Pressurisation ducts must be able to maintain an air supply to critical areas for the duration of the fire.
Air supply must be maintained, fire dampers cannot be used.
All ductwork penetrating fire compartments must be fire rated in order to maintain compartmentation.
Pressurisation plant should be in a dedicated plant room or separated from other equipment by a one hour fire resistant enclosure – BS 5588 part 4, clause 6.3.4.