Pressurisation duct work is a passive fire protection system. It is used to supply fresh air to any area of refuge, designated emergency evacuation or egress route.
The purpose of pressurisation ductwork is to maintain positive pressure in building spaces to prevent smoke from entering from other spaces in which a fire is occurring. It is typically used in exit stairways, corridors, and lobbies.
Pressurisation ductwork is certified on the basis of fire testing such as ISO 6944.
There are two means of providing fire-resistance rated ductwork: