Greg,
I'd probably follow Matt's concept. I don't want to take on the
perception that I'm engineering a solution, merely that I'm following a
prescriptive document and listing.
I might ask the question of someone at the manufacturer though.
*Ken Wagoner, SET
*Parsley Consulting***
*350 West 9th Avenue, Suite 206
*Escondido, California 92025
*****Phone 760-745-6181*
Visit our website <http://www.parsleyconsulting.com/> ***
On 09/03/2015 8:38 AM, Matt Grise wrote:
The main issue is whether one prefers to follow the letter/intent of the code
as a designer, or take on the risk of engineering a new application that has
not been thoroughly tested.
If the obstructions are not protected the way NFPA 13 and/or the specific
listing dictates, then it would seem that the design is a new 'engineered'
approach.
It is not to say that one way would or would not work... it is just a different
level of responsibility for the outcome.
Matt Grisé PE*, LEED AP, NICET II
Sales Engineer
Alliance Fire Protection
130 w 9th Ave.
North Kansas City, MO 64116
*Licensed in KS & MO
913.888.0647 ph
913.888.0618 f
913.526.7443 cell
www. AFPsprink.com
-----Original Message-----
From: Sprinklerforum [mailto:[email protected]] On
Behalf Of Gregg Fontes
Sent: Thursday, September 03, 2015 10:32 AM
To: [email protected]
Subject: RE: Larger circular duct obstructions
Ken,
So you would installed the ESFR sprinkler directly under the center point of the round
duct. (i.e. the 84" diameter duct, the sprinkler would be at 42" from the edge
at the listed distance below.) Would a round duct collect enough head to set this off???
Thanks,
Gregg Fontes
Cen-Cal Fire Systems, Inc.
209-334-9119
-----Original Message-----
From: Sprinklerforum [mailto:[email protected]] On
Behalf Of Parsley Consulting
Sent: Thursday, September 03, 2015 6:46 AM
To: [email protected]
Subject: Re: Larger circular duct obstructions
Greg,
A couple of thoughts come to mind for me.
First, I would regard the large circular duct as similar to unobstructed
construction. The location of the deflector of the sprinklers below the duct
would have to be as called out in 8.12.4.1.
So, for those purposes the position below the duct would be driven by the
k-factor you're using.
Second, the use of an ESFR system to protect LH/OH occupancies is allowed by
12.6.7.1, provided that the original design was per the criteria in chapters 12 through
20. I don't think the manufacturers are going to stand behind designing ESFR's to meet
obstruction rules for standard spray sprinklers. To my way of thinking the continuous
obstruction rules of 8.12.5.3.1 would still be applicable. I don't agree that it would
be possible to eliminate the concern over obstructions less than 48" wide, as items
(3) and (4) of that section suggest 24" is the cutoff width.
I don't know if that's correct, however those are my initial thoughts.
*Ken Wagoner, SET
*Parsley Consulting***
*350 West 9th Avenue, Suite 206
*Escondido, California 92025
*****Phone 760-745-6181*
Visit our website <http://www.parsleyconsulting.com/>
***
On 09/02/2015 2:18 PM, Gregg Fontes wrote:
Looking at a building that has ESFR fire sprinkler protection. Half
is being used as open office area. They are installing circular ducts
from 32" to 84" diameter with the top of the duct approximately 36"
below the ESFR deflector (right below the roof trusses). In reading
8.12.5.3 2013 edition, in most cases if not all, Table 8.12.5.1.1
cannot be met, so sprinklers will need to be installed under the
ducts. With the duct being 32" to 84" diameter, where would the fire
sprinkler be placed? Per NFPA 13 is a flat barrier required to be
installed under the circular duct? FM give you a guideline, but 13
does not. Owner does not want the ESFR sprinklers change out, so
again where would you place the sprinkler and/or is a flat barrier
required by NFPA 13? (With a flat obstruction you can either be under
it or within so many inches of the end, but a huge diameter
obstruction, is it the edge, center ,etc.?)
Second thought, since this is no longer a storage application, can you
apply the standard spray sprinkler obstruction rules? (This still
does not state where to install the sprinkler below the obstruction,
but you could eliminate the obstruction less than 48".)
Thanks,
Gregg Fontes
Cen-Cal Fire Systems, Inc.
209-334-9119
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