Commercial Building Inspector B2Public Safety and Special ConstructionHard
A new Group R-2 apartment building is being constructed with a fire alarm system. According to NFPA 72 requirements adopted by the IBC, which of the following statements regarding the audibility of fire alarm notification appliances in sleeping areas is correct?
- AA minimum sound level of 70 dBA at the pillow.
- BA minimum sound level of 90 dBA at the pillow.
- CA minimum sound level of 75 dBA at the pillow.
- DA minimum sound level of 85 dBA at the pillow.
Show answer & explanationAnswer & explanation
Correct answer: C. A minimum sound level of 75 dBA at the pillow.
NFPA 72 (2019 edition, Section 18.4.5.3.2) requires that the audible notification appliance in sleeping areas produce a sound level of at least 75 dBA at the pillow, or at least 15 dBA above the average ambient sound level, whichever is greater, measured at the sleeping area.
Why the other options are wrong
- A. 70 dBA is insufficient; 75 dBA is the minimum required.
- B. 90 dBA is significantly higher than the minimum requirement and could be excessively loud.
- D. 85 dBA is higher than the minimum requirement, though it would be compliant.
Fire Alarm Audibility (Sleeping Areas)
Fire alarm notification appliances in sleeping areas must provide a minimum sound level of 75 dBA at the pillow, or 15 dBA above the average ambient sound level, to ensure occupants are adequately alerted.
- Critical for waking occupants, especially during sleep.
- Measurement taken at the pillow level.
- NFPA 72 sets the standard for audibility.
- Visual alarms (strobes) are also required for hearing-impaired individuals.
Memory trick: Seventy-five at the pillow, no less, for a safe night's rest.