Smoke Detector Placement for Magnetic Door Holders

Smoke detector placement is important when designing a fire life safety system for obvious reasons.  In this article, we are going to focus on the smoke detector placement requirements per NFPA 72 2010 edition for smoke doors with magnetic door holders.  If you are using smoke detectors for the purpose of door releasing service than the following code shall apply:

NFPA 72 2010 edition:

17.7.5.6.5.1 (A)
If the depth of the wall section above the door is 24 inches (610 mm) or less, one ceiling mounted smoke detector shall be required on one side of the doorway only, or two wall mounted smoke detectors shall be required, one on each side of the doorway.

17.7.5.6.5.1 (B)
If the depth of the wall section above the door is greater than 24 inches (610 mm) on one side only, one ceiling mounted smoke detector shall be required on the higher side of the doorway only, or two wall mounted smoke detectors shall be required, one on each side of the doorway.

17.7.5.6.5.1 (C)
If the depth of the wall section above the door is greater than 24 inches (610 mm) on both sides, two ceiling mounted smoke detectors or two wall mounted smoke detectors shall be required.  One on each side of the doorway.

In the above picture, you can clearly see that the header or space above the doorway with magnetic door holders is less than 24 inches (610 mm).  However, the installing fire life safety company installed a smoke detector on the ceiling on both sides of the doorway.  This smoke detector placement is not required but it never hurts to have extra coverage.  Just thought I would point it out.