If only the space under raised floors is to be protected by a total flooding system, which agent shall be used?

• A. An inert gas
• B. A halogenated agent
• C. Water mist
• D. Foam

Answer: (A)

In a total flooding system that protects only the space under raised floors, an inert gas is the best choice. This type of system works by displacing or reducing heat in the protected space without relying on toxic byproducts, which is important in a subfloor plenum that may house cables and equipment. Inert gas systems are designed to protect such spaces while keeping any potential exposure to occupants or equipment safe and minimizing corrosion or residue that other agents can cause.

Halogenated clean agents, while effective in many rooms, can release toxic byproducts and may be harsher on electrical equipment and ductwork, making them less desirable for underfloor voids. Water-based options like water mist or foam are not regarded as clean agent total flooding approaches and can damage sensitive electronics and wiring in enclosed floor spaces.