Temp ratings of sprinklers based on distance from heat sources 2013 ed.

[Zachary Siegrist]

I have a job where the heads ( ordinary temp) are less than 1 ft 0 in from
the edge of a downward discharge diffuser throughout the space. The
contractor has supplied me letter from the HVAC company stating that the
air discharged out of the diffusers are less than 100F and therefore the
heads do not need to be switched out or relocated to meet the specified
distances in Table 8.3.2.5(a). I believe he is trying to use Item 9 under
8.3.2.5 stating “*ordinary temperature sprinklers located adjacent to a
heating duct that discharges air that is less than 100F are not required to
be separated in accordance with Table 8.3.2.5(a)*.”


My question is this: a diffuser is listed under the heating duct category
in the ‘type of heat condition’ column in Table 8.3.2.5 (a). Are diffusers
viewed differently than the ductwork itself? Any thoughts as to if the
previously referenced section applies to sprinklers located adjacent to
diffusers or just sprinklers located adjacent to heating ducts? Typically
heads are just switched out to intermediate temperature sprinklers but this
is the first time someone has taken this approach.

Zach

[Roland Huggins]

Both. WE submitted this after trying to convince an AHJ that with a heat pump (aka low temp air), there was no need for separation. It was initiated by the discharge diffuser but the duct itself will not be radiating a higher temperature so the allowance applies overall.

Apply the NFPA caveat required for committee members when writing their own opinions, not a formal interpretation of the NFPA or any of its technical committees.

Roland


Roland Huggins, PE - Senior VP Engineering
American Fire Sprinkler Assn.
Dallas, TX
http://www.firesprinkler.org <http://www.firesprinkler.org/>

Fire Sprinklers Saves Lives

I have a job where the heads ( ordinary temp) are less than 1 ft 0 in from the edge of a downward discharge diffuser throughout the space. The contractor has supplied me letter from the HVAC company stating that the air discharged out of the diffusers are less than 100F and therefore the heads do not need to be switched out or relocated to meet the specified distances in Table 8.3.2.5(a). I believe he is trying to use Item 9 under 8.3.2.5 stating “ordinary temperature sprinklers located adjacent to a heating duct that discharges air that is less than 100F are not required to be separated in accordance with Table 8.3.2.5(a).”
My question is this: a diffuser is listed under the heating duct category in the ‘type of heat condition’ column in Table 8.3.2.5 (a). Are diffusers viewed differently than the ductwork itself? Any thoughts as to if the previously referenced section applies to sprinklers located adjacent to diffusers or just sprinklers located adjacent to heating ducts? Typically heads are just switched out to intermediate temperature sprinklers but this is the first time someone has taken this approach.
Zach
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[Zachary Siegrist]

Thank you Roland for your response and some background on the topic.

Zach

Post by Roland Huggins
Both. WE submitted this after trying to convince an AHJ that with a heat
pump (aka low temp air), there was no need for separation. It was
initiated by the discharge diffuser but the duct itself will not be
radiating a higher temperature so the allowance applies overall.
Apply the NFPA caveat required for committee members when writing their
own opinions, not a formal interpretation of the NFPA or any of its
technical committees.
Roland
Roland Huggins, PE - Senior VP Engineering
American Fire Sprinkler Assn.
Dallas, TX
http://www.firesprinkler.org
Fire Sprinklers Saves Lives
I have a job where the heads ( ordinary temp) are less than 1 ft 0 in from
the edge of a downward discharge diffuser throughout the space. The
contractor has supplied me letter from the HVAC company stating that the
air discharged out of the diffusers are less than 100F and therefore the
heads do not need to be switched out or relocated to meet the specified
distances in Table 8.3.2.5(a). I believe he is trying to use Item 9
under 8.3.2.5 stating “*ordinary temperature sprinklers located adjacent
to a heating duct that discharges air that is less than 100F are not
required to be separated in accordance with Table 8.3.2.5(a)*.”
My question is this: a diffuser is listed under the heating duct
category in the ‘type of heat condition’ column in Table 8.3.2.5 (a).
Are diffusers viewed differently than the ductwork itself? Any thoughts
as to if the previously referenced section applies to sprinklers located
adjacent to diffusers or just sprinklers located adjacent to heating
ducts? Typically heads are just switched out to intermediate temperature
sprinklers but this is the first time someone has taken this approach.
Zach
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[AKS-Gmail-IMAP]

Heat pump systems do not have a thermal cutoff switch like electric or natural gas heat systems that turn the system off on high heat. It is actually quite possible that a heat pump system designed to produce a 40 F delta T will do exactly that when 100 F return air gets back to the system. The discharge air will be 140 F. The manufacturers and some HVAC engineers will say this condition would not occur, but that is not the case because installations can have enough mistakes in them to produce the high heat condition. Just ask them to show you the high heat safety control elements in the system circuit. It will not be there because the safety requirement comes from fire safety and not from sprinklers too close.

Allan Seidel
St. Louis, MO

Post by Zachary Siegrist
Thank you Roland for your response and some background on the topic.
Zach
Both. WE submitted this after trying to convince an AHJ that with a heat pump (aka low temp air), there was no need for separation. It was initiated by the discharge diffuser but the duct itself will not be radiating a higher temperature so the allowance applies overall.
Apply the NFPA caveat required for committee members when writing their own opinions, not a formal interpretation of the NFPA or any of its technical committees.
Roland
Roland Huggins, PE - Senior VP Engineering
American Fire Sprinkler Assn.
Dallas, TX
http://www.firesprinkler.org <http://www.firesprinkler.org/>
Fire Sprinklers Saves Lives

I have a job where the heads ( ordinary temp) are less than 1 ft 0 in from the edge of a downward discharge diffuser throughout the space. The contractor has supplied me letter from the HVAC company stating that the air discharged out of the diffusers are less than 100F and therefore the heads do not need to be switched out or relocated to meet the specified distances in Table 8.3.2.5(a). I believe he is trying to use Item 9 under 8.3.2.5 stating “ordinary temperature sprinklers located adjacent to a heating duct that discharges air that is less than 100F are not required to be separated in accordance with Table 8.3.2.5(a).”
My question is this: a diffuser is listed under the heating duct category in the ‘type of heat condition’ column in Table 8.3.2.5 (a). Are diffusers viewed differently than the ductwork itself? Any thoughts as to if the previously referenced section applies to sprinklers located adjacent to diffusers or just sprinklers located adjacent to heating ducts? Typically heads are just switched out to intermediate temperature sprinklers but this is the first time someone has taken this approach.
Zach
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Sprinklerforum mailing list
http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org <http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org>

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