I agree with Kevin’s assessment as well. But we were not discussing droplet scatter or if suppression would even be achieved.
I feel we often overlook the “Beam Rule” having 2 requirements. One of which must be met. Distance per the table, or sprinklers spaced on both sides. Great discussion. I feel you framed you question to elicit a literal reading and response. Bravo Anthony. Well played sir! R/ Matt Please rate our customer service<https://survey.medallia.com/?emailsignature&fc=3539&bg=Fire%20and%20Fabrication> Matthew J. Willis, CWBSP, CET Engineering Designer IV FERGUSON FIRE DESIGN, LLC A Wholly Owned Subsidiary of Ferguson Fire & Fabrication, LLC 401 N 5th Street Suite 448 Wausau, WI 54403 C: 307-236-8249 matthew.will...@ferguson.com<mailto:matthew.will...@ferguson.com> www.FergusonFire.com<http://www.fergusonfire.com/> From: Anthony Johnson <mountainfirepr...@gmail.com> Sent: Friday, March 10, 2023 8:29 AM To: Discussion list on issues relating to automatic fire sprinklers <sprinklerforum@lists.firesprinkler.org> Subject: [Sprinklerforum] Re: Duct obstruction criteria in LH attic In our situation we are 3" above the duct but can locate the uprights as far as 2 ft away horizontally. The next line of sprinklers would exceed the halfway point to the duct IF the duct posed as an obstruction. I agree with Kevin Hall's assessment however I'm also thinking ahead when the inspector questions it and want to make sure I'm justified in my position. I might add sprinklers just to avoid having a discussion with the inspector on a topic that obviously has many different opinions. I think there are good arguments on both sides but I think the code makes it obvious in a roundabout way. At the very least I would hope for an additional little "AHJ FAQ" in the handbook as found in the commentaries - even though they don't carry weight it would be helpful. [https://s-install.avcdn.net/ipm/preview/icons/icon-envelope-tick-green-avg-v1.png]<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free.www.avg.com<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> On Fri, Mar 10, 2023 at 8:12 AM <matthew.will...@ferguson.com<mailto:matthew.will...@ferguson.com>> wrote: The one number I do not recall in this discussion is the distance horizontally. I guess based on the pretty picture in Figure A.9.5.5.1, I am having trouble seeing how a deflector at only 3” above gets water on the other side of a 24” duct. If the sprinkler is 2” from the duct, like happens in an attic, is it still your position that water will get on the other side? R/ Matt Please rate our customer service<https://survey.medallia.com/?emailsignature&fc=3539&bg=Fire%20and%20Fabrication> Matthew J. Willis, CWBSP, CET Engineering Designer IV FERGUSON FIRE DESIGN, LLC A Wholly Owned Subsidiary of Ferguson Fire & Fabrication, LLC 401 N 5th Street Suite 448 Wausau, WI 54403 C: 307-236-8249 matthew.will...@ferguson.com<mailto:matthew.will...@ferguson.com> www.FergusonFire.com<http://www.fergusonfire.com/> From: Kevin Hall <kh...@firesprinkler.org<mailto:kh...@firesprinkler.org>> Sent: Thursday, March 9, 2023 6:38 PM To: Discussion list on issues relating to automatic fire sprinklers <sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>> Subject: [Sprinklerforum] Re: Duct obstruction criteria in LH attic I’m not sure where you are getting that requirement from the annex section: A.10.2.7.3.1.4 It is the intent of this section to exempt nonstructural elements in light and ordinary hazard occupancies from the obstruction criteria commonly called the “Three Times Rule.” However, the other obstruction rules, including the “Beam Rule” (see 10.2.7.2<https://link.nfpa.org/publications/13/2022/chapters/10#ID000130001317>) and the “Wide Obstruction Rule” (see 10.2.7.4.2<https://link.nfpa.org/publications/13/2022/chapters/10#ID000130001351>), still apply. If an obstruction is so close to a sprinkler that water cannot spray on both sides, it is effectively a continuous obstruction as far as the sprinkler is concerned and the Beam Rule should be applied. It is not the intent of this section to permit the use of fixtures and architectural features or treatments to conceal, obscure, or otherwise obstruct sprinkler discharge. The requirement should be applied in accordance with the performance objectives in 10.2.7.1<https://link.nfpa.org/publications/13/2022/chapters/10#ID000130001315>. The annex specifically states it IS the intent to EXEMPT nonstructural elements in light and ordinary hazard occupancies from the three times rule. IF the obstruction was at or above the level of the deflector, then the beam rule would apply, but this deflector is above the obstruction so water is able to spray on both sides of the obstruction, creating a noncontinuous obstruction, so the beam rule does NOT apply. IF the obstruction was wider than 4 ft, then the wide obstruction rule would apply, but this obstruction is 2 ft wide, so no additional protection is required. The last paragraph of the annex defers to the requirements in 10.2.7.1 which state, “Sprinklers shall be located so as to minimize obstructions to discharge as defined in 10.2.7<https://link.nfpa.org/publications/13/2022/chapters/10#ID000130001314>, or additional sprinklers shall be provided to ensure adequate coverage of the hazard.” The obstruction is minimized based on the position of the sprinkler deflector above the obstruction, and adequate coverage is provided for the hazard present. It is a light hazard occupancy — low quantity and low combustibility — it is NOT the intent of the installation and obstruction rules to get every inch of the floor wet. There will be shadow areas, but the thermodynamic properties of the water spray converting to steam will provide plenty of cooling to achieve adequate fire control. [https://www.dropbox.com/s/g4h8r7hdtsr6154/AFSA_L.png?raw=1] Kevin Hall, M.Eng., P.E., ET, CWBSP, PMSFPE Sr. Manager, Engineering and Technical Services American Fire Sprinkler Association p: 214-349-5971 w: firesprinkler.org<http://firesprinkler.org> [http://cdn2.hubspot.net/hubfs/184235/dev_images/signature_app/facebook_sig.png]<https://www.facebook.com/firesprinkler.org/> [http://cdn2.hubspot.net/hubfs/184235/dev_images/signature_app/twitter_sig.png] <https://twitter.com/afsa/status/1039528345367732224> [http://cdn2.hubspot.net/hubfs/184235/dev_images/signature_app/linkedin_sig.png] <https://www.linkedin.com/company/american-fire-sprinkler-association-afsa-/> [http://cdn2.hubspot.net/hubfs/184235/dev_images/signature_app/instagram_sig.png] <https://www.instagram.com/firesprinklerorg/> AFSA is on the move! Our new address is 1410 East Renner Rd., Suite 150, Richardson, TX 75082 Advanced Sprinkler Hydraulic Calculations Take a deep dive into advanced hydraulic principles for standpipe systems, fire pump assemblies, and water storage tanks. Learn more and register for the May 3-5 class here<https://www.firesprinkler.org/programs/advanced-sprinkler-hydraulic-calculations-workshop/>. On Thu, Mar 9, 2023 at 8:13 PM Brett Peters <br...@proudline.ca<mailto:br...@proudline.ca>> wrote: The annex clarifies that any object within the 18” is considered an obstruction and you are required to use the 3X or bean rule On Thu, Mar 9, 2023 at 4:51 PM Kevin Hall <kh...@firesprinkler.org<mailto:kh...@firesprinkler.org>> wrote: Dane is correct. We get this question a lot through the Technical Review submissions, and the response is pretty cut and dry. The three times rule does not apply to non structural members in light and ordinary hazard occupancies and because the deflector is located above the duct, water is able to spray on both sides, so it can be considered a noncontinuous obstruction. No additional protection is not required. -Kevin On Thu, Mar 9, 2023 at 5:08 PM Greg McGahan <g...@genesisfireservices.com<mailto:g...@genesisfireservices.com>> wrote: With all due respect Dane - read the annex, it specifically addresses that issue. On Thu, Mar 9, 2023 at 3:42 PM Dane Long <da...@bamfordfire.com<mailto:da...@bamfordfire.com>> wrote: Anthony, I feel there might be a few sections you need to look at regarding this question. For me I would start at 8.6.5.2<http://8.6.5.2> Obstructions to Sprinkler Discharge Pattern Development. 8.6.5.2.1.1 Continuous or noncontinuous obstructions less than or equal to 18 in. (457 mm) below the sprinkler deflector that prevent the pattern from fully developing shall comply with 8.6.5.2<http://8.6.5.2>. The section above lays the ground work for the 18in requirement (8.6.5.2<http://8.6.5.2>). Then I would look at 8.6.5.2.1.3* Minimum Distance from Obstructions. 8.6.5.2.1.4* For light and ordinary hazard occupancies, structural members only shall be considered when applying the requirements of 8.6.5.2.1.3. IMHO Because it specifically says “structural members only shall be considered” I believe the intent of this section is to allow for us to not provide sprinklers on both side to a reasonable degree, meaning we’re able to get water on both sides of the obstruction as long as its not a structural member. Thanks, [cid:image001.jpg@01D9532B.C20050C0] [cid:image002.png@01D9532B.C20050C0] Dane Long, AET Engineering Technician | Bamford Fire Sprinkler Co., Inc. P: 785.825.7710 F: 785.825.0667 A: 1383 W. North Street Salina, KS 67401<https://www.google.com/maps/search/1383+W.+North+Street%C2%A0+Salina,+KS%C2%A0+67401?entry=gmail&source=g> From: Anthony Johnson <mountainfirepr...@gmail.com<mailto:mountainfirepr...@gmail.com>> Sent: Thursday, March 9, 2023 2:26 PM To: Discussion list on issues relating to automatic fire sprinklers <sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>> Subject: [Sprinklerforum] Re: Duct obstruction criteria in LH attic The 3x rule is the only one we think would apply but it only applies to structural components. Best Regards, Anthony Johnson Mountain Fire Protection 'Saving Lives and Valuing Property' On Thu, Mar 9, 2023 at 12:58 PM Taylor Schumacher <tay...@sfsprinkler.com<mailto:tay...@sfsprinkler.com>> wrote: When you cannot apply one of the obstruction rules, it does not mean that there isn’t an obstruction. If you think about this scenario the same way you would with sprinklers directly attached to a pipe, that’s where to start. Look at the 3x rule or sprinklers on each side. Taylor Schumacher Security Fire Sprinkler<http://www.j-berd.com/> 1 Industrial Blvd | Sauk Rapids, MN 56379<https://www.google.com/maps/search/1+Industrial+Blvd+%7C+Sauk+Rapids,+MN+56379+Office:+320?entry=gmail&source=g> Office: 320<https://www.google.com/maps/search/1+Industrial+Blvd+%7C+Sauk+Rapids,+MN+56379+Office:+320?entry=gmail&source=g>.656.0847 | Direct: 320.640.7050 From: matthew.will...@ferguson.com<mailto:matthew.will...@ferguson.com> <matthew.will...@ferguson.com<mailto:matthew.will...@ferguson.com>> Sent: Thursday, March 09, 2023 12:37 PM To: sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org> Subject: [Sprinklerforum] Re: Duct obstruction criteria in LH attic I believe however, the intent of the section must still be applied. Water on both sides. Not sure in the 13 edition the location, but in the 19 it is 10.2.7.1.2. We are referred back to it as applicable from the 3 times section. Sprinklers spaced on opposing sides, not to exceed the max half distance. R/ Matt Please rate our customer service<https://survey.medallia.com/?emailsignature&fc=3539&bg=Fire%20and%20Fabrication> Matthew J. Willis, CWBSP, CET Engineering Designer IV FERGUSON FIRE DESIGN, LLC A Wholly Owned Subsidiary of Ferguson Fire & Fabrication, LLC 401 N 5th Street Suite 448 Wausau, WI 54403 C: 307-236-8249 matthew.will...@ferguson.com<mailto:matthew.will...@ferguson.com> www.FergusonFire.com<http://www.fergusonfire.com/> From: Anthony Johnson <mountainfirepr...@gmail.com<mailto:mountainfirepr...@gmail.com>> Sent: Thursday, March 9, 2023 11:24 AM To: sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org> Subject: [Sprinklerforum] Duct obstruction criteria in LH attic I have an elementary question but know there are varying opinions on the topic. The situation is a tight unused attic space in a LH occupancy. Our upright sprinkler deflector will be 3" above the ductwork. Evaluating all of the obstruction criteria presented in NFPA we've essentially came to the conclusion that the ductwork would not pose an obstruction but came to this conclusion mainly by process of elimination. The beam-rule would not apply since the ductwork is below the deflector. The 3X rule is only for structural components in light and ordinary hazards and the 'wide obstruction' rule would not apply since the ductwork is only 24" wide. That only leaves the 'suspended or floor mounted vertical obstructions' rule of 8.6.5.2.2 ('2013 ed) but it specifically mentions free standing partitions, privacy curtains and "similar obstructions". I don't think duct-work is a similar obstruction. I would like to have my ducks in a row if this design approach should be questioned but also want to make sure I have a sound design. Is our reasoning correct that essentially if the sprinkler deflector is above the duct water will spray on both sides and the duct would not pose as an obstruction? Best Regards, Anthony Johnson Mountain Fire Protection 'Saving Lives and Valuing Property' _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org> To unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org<mailto:sprinklerforum-le...@lists.firesprinkler.org> _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org> To unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org<mailto:sprinklerforum-le...@lists.firesprinkler.org> -- Greg McGahan Genesis Fire Services, LLC 4912 Glover Lane. Milton, FL <https://www.google.com/maps/search/4912+Glover+Lane.+Milton,+FL%C2%A0+32570?entry=gmail&source=g> 32570<https://www.google.com/maps/search/4912+Glover+Lane.+Milton,+FL%C2%A0+32570?entry=gmail&source=g> P- 850-637-8535 C- 850-712-9555 _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org> To unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org<mailto:sprinklerforum-le...@lists.firesprinkler.org> -- Kevin Hall, M.Eng., P.E., ET, CWBSP, PMSFPE Sr. Manager, Engineering and Technical Services American Fire Sprinkler Association _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org> To unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org<mailto:sprinklerforum-le...@lists.firesprinkler.org> -- Thank You Brett Peters PFPS Ltd (780) 777 0568 Sent From My iPhone _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org> To unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org<mailto:sprinklerforum-le...@lists.firesprinkler.org> _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org> To unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org<mailto:sprinklerforum-le...@lists.firesprinkler.org>
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