I hear what Ed is saying but I believe the only correct answer is someone hire 
an alarm contractor to test and certify their portion.  It is NOT up to the 
sprinkler guy to test the fire alarm equipment. I surely wouldn't accept it if 
you sent me fire alarm testing.  And it's not up to either you or the alarm guy 
to make the air work correctly. You are responsible for the solenoid through 
the through the sprinklers.  Plainly speaking if it has H2O in it it's your, if 
it has electrons in it it's an alarm issue.  If you test and certify are you 
prepared to accept other trades work?  Not likely. 

Chris Cahill, PE*
Associate Fire Protection Engineer 
Burns & McDonnell
Phone:  952.656.3652
Fax:  952.229.2923
[email protected]
www.burnsmcd.com
*Registered in: MN


Proud to be #14 on FORTUNE's 2014 List of 100 Best Companies to Work For

-----Original Message-----
From: Sprinklerforum [mailto:[email protected]] On 
Behalf Of Ed Vining
Sent: Tuesday, April 07, 2015 12:42 PM
To: [email protected]
Subject: Re: preaction HVAC detector testing

Judging the lack of response to your question I don’t think anyone else wants 
to tackle it. I’m modifying my response and responding back through the forum 
in hopes of stimulating interest.



On the surface it doesn't feel good. I am confused about the airflow described. 
It seems that the supply air is ducted from an HVAC unit in the room to the 
underfloor area,  passing through the floor openings into the room, through 
openings in the ceiling, with return air ducted from the ceiling back to the 
HVAC unit. There are area-type smoke detectors on the ceiling. I am not sure 
about the detectors under the floor.  By your words “duct-type smoke detectors” 
these may be only in the supply duct or ducts  in the underfloor.

Both the space above the ceiling and the underfloor space will have high air 
velocities.  Smoke from a fire in the overhead will be diluted by the airflow. 
It may be deleted further by makeup air at the HVAC unit. The diluted smoke 
will pass one or more of the underfloor duct detectors. Also, if a fire were to 
occur when the air system is down, there would be no detector protection of the 
overhead or underfloor.  This means the preaction system would not discharge 
water until smoke migrated to a detector.


It is unlikely that the performance of the smoke detectors would meet the 
expectations of the owner.

I am somewhat notorious for saying, “The damn system won’t work”. In this case 
it depends on the expectations.  If the ONLY task of the smoke detection is to 
provide the “trigger” to permit the preaction valve to open when a sprinkler 
operates (and the HVAC system is operating), the system should do its job.  If 
the system is to provide early warning to limit fire and smoke damage, it will 
not accomplish that.


There are holes in the floor to bring air into the room through equipment.
If there is a detector by each of these holes, smoke in the underfloor should 
be detected appropriately.  If smoke detectors in the underfloor are space as 
they are for normal room protection, it is likely that smoke can travel from 
the underfloor without passing a detector.  Ceiling area-type detectors will be 
looking at diluted smoke. Hopefully these detectors are present at each return 
grille.


This seems to be an area which would best be served by an air aspirating 
system.  Hopefully too, the air handling system is shut down when smoke causes 
an alarm.  This so the sprinklers will have a chance to operate sooner.


I’m not sure what your “Certification” is supposed to represent, but if it is 
to include some assurance the system will do its job, I think this one would 
not.  Even adding area-type smoke detectors would not be much of an improvement.


So what is the goal?  Without a goal there can’t be valid tests.

On Mon, Apr 6, 2015 at 6:18 AM, Charles G Key <[email protected]> wrote:

> Greetings, I have a project with an It room that has  sprinklers below 
> the raised floor, in the ceiling and above the ceiling. This is a 
> double interlock system and they have installed detectors below the 
> floor and in the ceiling. They are stating that the detection for the 
> area above the ceiling is in the duct detectors below the 
> floor.(supply). Since I am asked to certify the system, does anyone 
> have an idea on the proper method to test the detectors for the above 
> ceiling area? I could set off a smoke bomb above the ceiling, but how 
> much smoke should it take? Ideas?
>
>
>
> C.Gregg Key SET
> Key Fire Protection Enterprises,LLC
> 3200 Mike Padgett Hwy.
> Augusta, GA. 30906
> 706-790-3473 Office
> 706-738-2119 Facsimile
> 706-220-8821 Mobile
> [email protected]
>
>
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>
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> er.org
>



--
Ed Vining
4819 John Muir Rd
Martinez CA 94553
925-228-8792
Cell 925-787-0465
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