During a developing fire, sprinklers should be allowed to operate for how long to gain control?

During a developing fire, sprinklers should be allowed to operate for how long to gain control?

• A. 10 to 20 minutes
• B. 60 to 90 minutes
• C. 4 to 6 hours
• D. 24 hours

Answer: (B)

During a developing fire, sprinklers are expected to keep protecting the space by continuously applying water to absorb heat, cool nearby surfaces, and slow flame spread. Allowing the system to operate for about 60 to 90 minutes gives enough time for the fire to be contained and for occupants to evacuate while investigators or firefighters begin suppression actions. The other timeframes are not practical: 10–20 minutes is usually not long enough for the cooling and water application to blunt growth, while several hours or a full day would risk excessive water damage and safety concerns without additional protective benefit.

During a developing fire, sprinklers are expected to keep protecting the space by continuously applying water to absorb heat, cool nearby surfaces, and slow flame spread. Allowing the system to operate for about 60 to 90 minutes gives enough time for the fire to be contained and for occupants to evacuate while investigators or firefighters begin suppression actions. The other timeframes are not practical: 10–20 minutes is usually not long enough for the cooling and water application to blunt growth, while several hours or a full day would risk excessive water damage and safety concerns without additional protective benefit.