How is room size related to the required agent weight in a clean agent system?

• A. Larger room volume requires more agent to reach the target design concentration; weight is proportional to volume and design concentration, adjusted for leakage and room integrity.
• B. Larger room has no effect on agent weight.
• C. Weight depends only on ceiling height.
• D. Smaller rooms require more agent than larger rooms.

Answer: (A)

The main idea is that how much clean agent you need is tied to how big the space is and what concentration you’re aiming for. The target is a design concentration, which is the percent of the room air you want to be the agent. To reach that concentration in a room, you must supply an amount of agent roughly proportional to the room’s volume multiplied by the design concentration. If the room has leaks or openings, some of that agent will escape or be diluted, so you have to account for those losses and effectively increase the initial weight to still achieve the target concentration. In a tighter room with fewer leaks, you might need less agent to reach the same percentage.

That’s why the option stating that larger room volume requires more agent, with weight proportional to volume and design concentration and adjusted for leakage and room integrity, is the best description. The other ideas ignore how volume and concentration interact or imply that room size or height alone dictates the weight, which isn’t accurate.