Section 18.5.3/Visible Notification Appliance Placement
NFPA 72 Section 18.5 covers visible notification appliance (strobe) placement and candela requirements based on room size.
Visible notification appliances (strobes) must be located so that the flash is visible throughout the space. Wall-mounted strobes in rooms up to 20 feet by 20 feet require a minimum of 15 candela. Larger rooms require higher candela ratings or multiple appliances per Table 18.5.5.4.1(a). Strobes must be mounted between 80 and 96 inches above the finished floor (or 6 inches below the ceiling, whichever is lower). In sleeping areas, a 110 candela strobe is required at pillow level.
Why this section exists
Visible notification appliances alert hearing-impaired occupants and provide supplemental notification in noisy environments. The candela requirements are based on research into the minimum light intensity needed to attract attention in rooms of various sizes. Insufficient candela or incorrect placement can result in areas where the strobe flash is not visible, leaving occupants unaware of a fire alarm condition.
What plan reviewers look for
Plan reviewers check strobe locations on the reflected ceiling plan or fire alarm floor plan against the room dimensions. They reference Table 18.5.5.4.1(a) to verify that the candela rating is adequate for the room size. They check mounting heights and verify that sleeping areas (hotel rooms, dormitories) have the higher-candela strobes required by 18.5.5.5.
Common violations
Related NFPA 72 requirements
Section 18.4.5 covers audible notification appliances (horns). Section 17.5.3 covers smoke detector spacing. Table 18.5.5.4.1(a) provides the spacing and candela tables for wall-mounted strobes. Section 18.5.5.5 covers the specific requirements for sleeping areas.