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Small Room Design With Residential Sprinklers
"We are doing a NFPA 13 design with residential sprinklers. Section
11.3.1.3(2) allows calculating the area of coverage by the provisions of either
8.5.2.1 or 8.6.2.1.2. Does 8.6.2.1.2 apply to just pendent sprinklers or can
it be applied to sidewall sprinklers?"
We have reviewed the 2013 edition of NFPA 13 as the applicable standard. Our
informal interpretation is that it applies to all types of residential
sprinklers.
It is understandable that there is some confusion here because Section 8.6 is
just for pendent sprinklers. By Section 11.3.1.3 saying the provisions of
8.6.2.1.2 apply means it is the methodology that is being discussed. Keep in
mind that this section is referring to the half of the calculation where you
assign a density of 0.1 gpm/sq. ft. to the residential sprinkler. You still
have to perform a calculation based on the listing of sprinkler that accounts
for the needs of the different sprinkler types. This has been cleaned up for
the 2016 edition (see FR-261) that will say:
(3) In rooms or compartments 800 sq. ft. (74.3 sq. m) or less calculated based
on delivering a minimum of 0.1 gpm/sq. ft. (4.1 mm/min) over the room or the
compartment using the area of the room divided by the number of sprinklers in
the room.
This change emphasizes that it applies only to small rooms of no more than 800
sq. ft. (when larger you must use 8.5.2.1) and that it applies to all
residential sprinklers.
> On Apr 13, 2015, at 8:27 AM, John Denhardt <[email protected]>
> wrote:
>
> This was a lengthy discussion at a recent committee meeting. My position was
> it does not apply to sidewalls. Many of the committee said it did apply to
> sidewalls. For 2016, it should be clearer that it does apply to sidewalls.
>
> Sprinklers Save
>
>> On Apr 13, 2015, at 9:16 AM, Travis Mack <[email protected]> wrote:
>>
>> That section appears to apply to residential sprinklers in general. The
>> portion in chapter 11 (2013 edition) points you to a specific section to
>> describe area per sprinkler for residential sprinklers. I believe 2007 has
>> the same wording.
>>
>> The section in chapter 8 that is referenced is for SSP/SSU. But chapter 11
>> specifically points you to the section about area. It is my understanding
>> that it applies to residential sidewall and pendent.
>>
>> Will be interesting to see others opinion on this.
>>
>> Travis Mack, SET
>> MFP Design, LLC
>> "Follow" us on Facebook:
>> https://www.facebook.com/pages/MFP-Design-LLC/92218417692
>> Send large files to MFP Design via:
>> https://www.hightail.com/u/MFPDesign
>>
>> Sent from my iPhone
>>
>>> On Apr 13, 2015, at 6:00 AM, John Denhardt <[email protected]>
>>> wrote:
>>>
>>> Agree, but in my opinion this rule did not apply to sidewalls. However, the
>>> 2016 edition might be adding sidewalls specifically.
>>>
>>> Do not call about Stephs phoneSprinklers Save
>>>
>>>> On Apr 13, 2015, at 8:44 AM, Travis Mack <[email protected]> wrote:
>>>>
>>>> Dewayne:
>>>>
>>>> I don't have the references in front of me but can get later today if you
>>>> need.
>>>>
>>>> In NFPA 13, if you need the requirements for a small room, you can take
>>>> the area of the room divided by the number of sprinklers in the room to
>>>> get the area per sprinkler.
>>>>
>>>> You then compare that to the listing of your sprinkler and use whichever
>>>> is greater.
>>>>
>>>> For example, a 600 sq ft room with 4 residential sprinklers is 150 sq ft
>>>> per sprinkler. At 0.10 you have a minimum of 15 gpm. If sprinklers are 8'
>>>> off walls and no more than 16 ft apart, the listing for a 4.9k pendent is
>>>> 13 gpm so you use the 15 gpm from above.
>>>>
>>>> If your sprinklers at 9' off walls, then you use 17 gpm because that is
>>>> the listing for 18' spacing of a 4.9k sprinkler.
>>>>
>>>> I can find the exact references later today if you are unable to locate.
>>>> However, if you find where it says to do 4 sprinkler for residential
>>>> sprinklers, it is the next line or two down that points you to be the room
>>>> area method for standard spray that i mentioned above.
>>>>
>>>>
>>>> Travis Mack, SET
>>>> MFP Design, LLC
>>>> "Follow" us on Facebook:
>>>> https://www.facebook.com/pages/MFP-Design-LLC/92218417692
>>>> Send large files to MFP Design via:
>>>> https://www.hightail.com/u/MFPDesign
>>>>
>>>> Sent from my iPhone
>>>>
>>>>> On Apr 13, 2015, at 5:07 AM, Dewayne Martinez
>>>>> <[email protected]> wrote:
>>>>>
>>>>> It would but I am using residential pendant sprinklers and the small room
>>>>> rule only applies to standard throw sprinklers.
>>>>> I guess that's the tradeoff I need to deal with for only wanting to calc 4
>>>>> sprinklers and using extended coverage.
>>>>>
>>>>> -----Original Message-----
>>>>> From: Sprinklerforum
>>>>> [mailto:[email protected]] On Behalf Of John
>>>>> Denhardt
>>>>> Sent: Monday, April 13, 2015 6:46 AM
>>>>> To: <[email protected]>
>>>>> Subject: Re: NFPA 13 (07ed) apartment obstructions
>>>>>
>>>>> Does the small room apply? If so, use .05 x small room rule or listing
>>>>> whichever is larger.
>>>>>
>>>>> Sprinklers Save
>>>>>
>>>>>>> On Apr 13, 2015, at 7:38 AM, Dewayne Martinez
>>>>>> <[email protected]> wrote:
>>>>>>
>>>>>> Thanks for confirming Jerry. The light is small and It just looks
>>>>>> weird to have a head so far away from the center of the room where the
>>>>>> light is located. Of course when I have to offset the sprinkler so
>>>>>> much it affects my calculations since it is a 13 application. Glad
>>>>>> the salesman bid it as if there were no lights present :) Thanks,
>>>>>> Dewayne
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Sprinklerforum
>>>>>> [mailto:[email protected]] On Behalf Of
>>>>>> Jerry Van Kolken
>>>>>> Sent: Thursday, April 09, 2015 6:49 PM
>>>>>> To: [email protected]
>>>>>> Subject: RE: NFPA 13 (07ed) apartment obstructions
>>>>>>
>>>>>> Looks like your you using the 4x rule . You should only need a single
>>>>>> head at 36" away.
>>>>>>
>>>>>> Jerry Van Kolken
>>>>>> Millennium Fire Protection
>>>>>> (760) 722-2722
>>>>>>
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Sprinklerforum
>>>>>> [mailto:[email protected]]
>>>>>> On Behalf Of Dewayne Martinez
>>>>>> Sent: Thursday, April 09, 2015 10:16 AM
>>>>>> To: [email protected]
>>>>>> Subject: NFPA 13 (07ed) apartment obstructions
>>>>>>
>>>>>> I am using residential concealed pendant sprinklers in a NFPA 13
>>>>>> apartment complex. Many of the rooms have a surface mounted domed
>>>>>> light which is about 12in in diameter and 5in deep at the center. It
>>>>>> seems to me that I must maintain at least 36in away from the edge of
>>>>>> the light per figure
>>>>>> 8.10.6.2.1.3 or install a sprinkler on both sides correct?
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Dewayne
>>>>>> _______________________________________________
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>>>>>> er.o
>>>>>> rg
>>>>>>
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>>>>>> er.o
>>>>>> rg
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>>>>>> er.org
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