STANDARDS & FORMULAS

FA Auto Distribute

Fire alarm devices spread over the rooms you pick: detectors, call points and sounder-strobes.

Standards and regulations

NFPA 72
National Fire Alarm and Signaling Code
Detector spacing, manual call points, notification appliances and installation notes.

Formulas

Detector coverage

every point of the ceiling within 0.7 × S of a detector

S = the listed spacing (a heat detector’s S reduced under a high ceiling)

Design rules it applies

Smoke detectors as a rule; heat in kitchens, toilets and plant rooms; none in shafts
A manual call point within 1.5 m of each exit, and more until no walk to one is over 61 m
Sounder-strobes in corridors: 4.6 m from the ends, 30.5 m apart at most

For reference. MO.tool works these out to help your design; the engineer remains responsible for it. Always check the edition of each standard your project uses and the requirements of the local authority (DEWA, ADDC, Civil Defence…).

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