What is design concentration best described as?

• A. The target concentration in the protected space needed to achieve effective extinguishment
• B. The concentration in the agent cylinders
• C. The maximum allowable agent leakage
• D. The HVAC set point

Answer: (A)

Design concentration is the target percent by volume of clean agent in the protected space needed to achieve extinguishment under the design fire scenario. It’s the level the system aims to reach in the room to reliably suppress the fire, and it guides how much agent to store and how it should be released. This concentration is about the atmosphere inside the protected space, not the amount stored in cylinders, not a leakage limit, and not the HVAC settings. The other ideas describe storage quantities, leakage controls, or environmental controls, which aren’t what design concentration represents.