If ambient conditions prohibit smoke detectors, FACU protection would be provided by which method?

• A. Automatic heat detection
• B. Automatic smoke detection
• C. Manual activation only
• D. Audible alarms only

Answer: (A)

When ambient conditions make reliable smoke sensing impossible, the fire alarm system relies on automatic heat detection to initiate the FACU. Heat detectors respond to a rise in temperature or to a fixed high temperature, which is far less prone to nuisance alarms caused by dust, steam, or humidity than smoke detectors. This automatic sensing still activates the fire alarm system to notify the FACU, providing protection without requiring occupants to trigger anything.

Manual activation only would depend on someone noticing the fire and pulling a switch, which isn’t automatic protection. Audible alarms only don’t provide any detection or automatic initiation to the FACU. Automatic smoke detection would be ideal if conditions allowed, but when they don’t, automatic heat detection is the appropriate alternative.