# Smoke Detection - NYC



## Rlelectric86 (Aug 10, 2018)

Currently jobs have been coming up with the question about smoke detectors under raised floors.  Current job has data and power (208/120v) lines running under a raised non-air cooled floor.  No receptacles under the floor.  All terminations occur above floor in respected boxes.  My question is, is there a clear code which states that a smoke detector is required in these areas?  I found articles in NFPA 72 - 2010 which discuss spacing, but not requirements.  Could anyone shed light on this situation?  (For the record... we have been complying with the AHJ these issues, but it always nice to know a source)

Thank you.


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## cda (Aug 10, 2018)

So is the ahj requireing them under floor??

If so the ahj should cite either fire code or NFPA section where they make the requirement.


Normally not required.

Now the underfloor, do they activate a fire extinguishing system???


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## Rlelectric86 (Aug 10, 2018)

There has been an unclear explanation...  some will say smoke detectors are required because once you put wires under a raised flood it becomes like an IDF room.  Others say that because there is circulating air cooling system,  fire protection is not required. 

I'm just looking for a code that may, at bare minimum cover me.  The NFPA 72, like I said wasn't clear, so if anyone has an interpretation of the code, i would like to see it.


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## cda (Aug 10, 2018)

Will look in 72 and give you a section or two


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## Builder Bob (Aug 14, 2018)

NFPA 72 17.7.3.5 Raised Floors and Suspended Ceilings

Environmental Air


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## Builder Bob (Aug 14, 2018)

Just found your answer - https://library.ul.com/wp-content/u...ression-in-Data-Centers-white-paper_final.pdf

NFPA 75


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## cda (Aug 14, 2018)

Ok lets go backwards

First start with the adopted building code and fire code. If nothing there, nothing required.

If a contract is involved, what does it say.

NFPA 72 just tells you how to install a  system, so just by that, it could go either way.


Normally not required, unless there to trigger a fire extinguishing system, or owner wants added protection.


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