The illustration that follows depicts the application of an intumescent coating to a building slab through which electrical cabling and metal conduits are fitted.
Fire-Resisting Ductwork and Dampers Fire-rated ducts are used to complement and secure fire compartmentation. Properly rated fire-rated ventilation ducts can avoid fire and heat spread between two compartments . It is possible to prevent fire spread from one fire compartment to another, along stairways, rooms, and general access corridors, only if all building materials and structural elements share a common fire classification and fire resistance rating. There are two types of fire-resisting dampers, mechanical and intumescent. These are used in heating, ventilation, and air-conditioning systems. They are used to help in the prevention of fire spread inside the ductwork through fire- resistant walls and floors. In the event of a fire, these systems will close to prevent the transfer of fire and smoke
between compartments. The dampers can be closed by: • A rise in temperature will close the damper blades
• The damper can be connected to the fire alarm system that will close on activation • Intumescent material can be used that expands in heat and closes the damper
A mechanical damper is driven by moving parts and is activated by a thermal release mechanism. It can incorporate a device which is electrically driven by smoke sensors. An intumescent damper will close when heat is present. The intumescent material expands in heat which fuses the grille into a solid block which prevents fire spread.
©SHEilds – All rights reserved FC V 5 JUN 2021
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