Purpose.
The purpose shall be to accomplish the following:
a) Restrict the spread of smoke through air duct systems within a building or into a building from the
outside.
b) Restrict the spread of fire through air duct systems from the area of fire origin, whether located
within the building or outside.
c) Maintain the fire-resistive integrity of building components and elements such as floors, partitions,
roofs, walls, and floor- or roof-ceiling assemblies affected by the installation of air duct systems.
d) Minimize the ignition sources and combustibility of the elements of the air duct systems.
e) Permit the air duct systems in a building to be used for the additional purpose of emergency smoke
control.