# Duct Detector location



## AllWIRES (Apr 10, 2014)

I'm digging in the 72 and 90a. I can't find any requirement for spacing of duct detectors in relation to dampers. 

Also looking for spacing of the duct detector required for 2000 and greater cfm units. I thought it was required to be 36" before the first 90.

Help


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## cabletie (Feb 12, 2011)

The location should be on the paperwork that comes with the detector. 
Off the top of my head I think it is 6 duct widths away from fittings that will cause air turbulence in the duct such as 90's
It usually is not possible, but should be fine as long as you get the right CFM through the detector. Some inspectors here will make you prove it with a manometer.


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## Mountain Electrician (Jan 22, 2007)

This looks pretty good. 

http://www.systemsensor.com/en-us/Documents/DuctSmokeDetector_Application_Guide_HVAG53.pdf

6 duct widths is correct, I believe.


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