Which type of system will not provide adequate protection for stockpiles of contents with moderate release rates that are stacked to a height of 10 inches?

• A. Light hazard
• B. Ordinary hazard group 1
• C. Ordinary hazard group 2
• D. Extra hazard

Answer: (B)

The key idea here is how storage hazards and pile height raise the required sprinkler design density. Stockpiles that have a moderate heat release rate and are stacked to a height of 10 inches create a higher fuel load than light storage, so a more protective design is needed than the light category offers. Ordinary hazard groups are used for stored commodities with higher fuel loads, but the lower of those two groups (ordinary hazard group 1) does not provide enough design density for this scenario. In other words, this configuration exceeds what ordinary hazard group 1 is designed to handle, so it will not give adequate protection. Using ordinary hazard group 2 or a higher category would meet or exceed the needed protection, which is why ordinary hazard group 1 is the under-sized choice.