A96.  Openings for the intakes of outdoor air to all air handling systems, mechanical ventilation systems, pressurization systems of exit staircases and internal corridors, and smoke control systems shall be no less than 5m from any exhaust discharge openings.

A97.     A concealed space between the ceiling and floor above it, ceiling and roof, or raised floor and structural floor of a building may be used as a plenum provided that the concealed space contains only:

i.    Mineral-insulated metal-sheathed cable,  
ii.    Aluminum-sheathed cable,  
iii.    Copper-sheathed cable,  iv.     Rigid metal conduit,  
v.    Enclosed metal trunking,  
vi.    Flexible metal conduit,  
vii.    Liquid-tight flexible metal conduit in lengths not more than 2 m, or metal-clad cables; viii.     Communication cables for computers, television, telephone and intercommunication system;
ix.    Fire protection installations;
x.    Pipes of non-combustible material conveying non-flammable liquids

A98.   Duct penetrations of fire walls should be avoided. Approved fire dampers shall be provided where air ducts penetrate or terminate at openings in walls or partitions required to have a fire resistance rating of 1 hour or more depending on the fire rating of the wall.

A99.     A fire damper shall not be required for the following:

1. Clothes Dryer Exhaust Ducts
2. Hazardous Fume Exhaust Duct
3. Stairwell Pressurization Ducts iv. Smoke Extraction Ducts
4. Laundry and Trash Chutes

A100. Materials used in the construction of a ceiling plenum shall be noncombustible or shall be limited combustible having a flame spread index of not more than 25 and a maximum smoke developed index of 50.