What is a typical temperature rating for a sprinkler head in a light-hazard occupancy such as an office building?

• A. 120-140 F
• B. 135-165 F
• C. 100-120 F
• D. 180-200 F

Answer: (B)

Temperature rating is the trigger temperature at which a sprinkler head will release water, determined by its fusible link or glass bulb. In a light-hazard space like an office, normal ambient temperatures are well below mid-range heat levels, so you want a rating that won’t activate from everyday heat sources but will respond promptly in a real fire. A rating around 135–165 degrees Fahrenheit strikes that balance, providing reliable activation when a fire heats the environment without nuisance activations from equipment, lighting, or sun exposure. Ratings much lower would be prone to false activations, while much higher ratings could delay response in a developing fire.