well it didn't occur in 02 so it wouldn't be in OLD Tyco data. As
others have pointed out, the explicit reference in 13:11.3 is all the
fire power one needs.
Roland
On Nov 2, 2010, at 9:10 AM, Carrol Glimstad wrote:
Makes perfect sense to me! But, BUT what do I do when I look to
NFPA to give me
some fire power to help with convincing my plan reviewer and "they"
come back
with the response that small rooms are NOT allowed to be considered in
residential applications? I guess I'm assuming that when the
sprinkler head's
manufacturer's cut sheet states " a minimum discharge of 0.1 GPM/sq.
ft. over
the "design area" comprised of the four most hydraulically demanding
sprinklers
for actual coverage areas protected by the four sprinklers.", that
"actual"
means ACTUAL. Yes, my head is 10 feet off of two walls, but my flow
table on my
LFII cut sheet tells me that I can and that I'm gonna hit that back
wall as long
as I have the flow and pressure to back it up. But my actual
coverage area is
NOT 400 sq. ft.! Not even close.
It doesn't help my situation either when in the Tyco white paper on
"Residental
Sprinklers Used in NFPA 13, 2002 Applications", the author makes NO
reference at
all to 8.6.2.1.2. He only cites the S x L rule for determining
coverage areas.
(big sigh...)
Carrol Glimstad
Sierra Fire Design
________________________________
From: Roland Huggins <[email protected]>
To: [email protected]
Sent: Tue, November 2, 2010 8:33:30 AM
Subject: Re: Residential "Room Design Method"?
the reason it should stay in section 8.6 is because it is the hybrid
part of the
residential design whereby the 0.1 must also be checked (and that
part is being
treated like a spray sprinkler). Seems a little history lesson is
warranted
regarding WHY the 0.1 was added. Long,long ago ok only about 10 yrs
starting
with TIA 99-1.
If you remember back when there was no minimum density on
residential sprinklers
and effective densities were down around 0.03 gpm/sf, FM did some
testing and
had some of the test fail miserable. This lead to two primary
changes. One was
that the foam in the fire test was standardized for heat release
rate and the
dual discharge requirement of 0.1 gpm/sf and the listing criteria
was born. The
reason for the 0.1 was not due to the failure of the test (since
that was fixed
by the changes to the fire test standard). It was due to the
realization that
the residential sprinkler had been made acceptable for high rise
buildings
(residential of course) BUT THE FIRE TEST HAD A MAXIMUM DURATION OF
10 MINUTES.
Since then, the duration has been extended (to 30 minutes I believe)
but at the
time that posed a problem. Enter the old faithful light hazard
density to
rescue the day.
This sprinkler was now being designed for both the listing
residential criteria
(typically close to 0.05) and the good ole 0.1 following the SxL
rule. Since the
0.1 was being evaluated like a spray sprinkler, why would it not be
reasonable
and prudent to apply not just the SxL rule but all spray sprinkler
spacing
rules? It was reasonable and prudent so it became criteria.
Roland
On Nov 1, 2010, at 5:13 PM, Ben Young wrote:
That makes no sense. How did the committee allow a reference to
SSU/P
spacing criteria under residential sprinkler design. It just makes
so
little sense. I was thinking about it as I was driving home... If
this is
truly the intent of the code (to average the spacing of residential
heads in
small rooms) the correct (in my opinion) IE, non-confusing way to
do this
would be to put the same language in the Chapter 8 section about
residential
sprinklers or pull 8.6.2.1.2 back into 8.5 or anything other than
referencing residential design methods from SSU/P spacing rules.
I can't be the only person who thinks that doesn't make a lot of
sense, can
I?
I'm also shocked that I never noticed this before. Believe me, I
checked
the 2010 edition, thinking maybe it was a mistake that got
rectified, etc.
So I guess part of this is sour grapes too.
Benjamin Young
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