MeyerFire
  • Blog
  • Daily
  • Exam Prep
    • CFPS Tools
    • NICET Tools
    • PE Forum & Errata
    • PE Problems
    • PE Store
    • PE Tools
    • PE Prep Series
  • TOOLS
    • TOOLKIT (FREE TRIAL)
    • *TOOLKIT (PURCHASE)
    • SUBMIT AN IDEA
    • BACKFLOW DATABASE*
    • CLEAN AGENT ESTIMATOR
    • CLOUD CEILING CALCULATOR
    • DOMESTIC DEMAND
    • FIRE PUMP ANALYZER
    • FIRE PUMP DATABASE*
    • FIRE FLOW CALCULATOR*
    • FRICTION LOSS CALCULATOR
    • HANGER SPACER
    • IBC TRANSLATOR*
    • K-FACTOR SELECTOR
    • NFPA 13 EDITION TRANSLATOR ('19 ONLY)
    • NFPA 13 EDITION TRANSLATOR ('99-'19)*
    • LIQUIDS ANALYZER*
    • OBSTRUCTION CALCULATOR
    • OBSTRUCTIONS AGAINST WALL*
    • PLUMBING FIXTURE COUNTS
    • REMOTE AREA ANALYZER
    • QUICK RESPONSE AREA REDUCTION
    • SPRINKLER DATABASE*
    • SPRINKLER FLOW*
    • TEST & DRAIN CALCULATOR
    • THRUST BLOCK CALCULATOR
    • TRAPEZE CALCULATOR
    • UNIT CONVERTER
    • VOLUME & COMPRESSOR CALCULATOR
    • WATER SUPPLY (US)
    • WATER SUPPLY (METRIC)
  • CODE CALLS
  • LOGIN
  • STORE
  • About
Picture
A FORUM FOR FIRE PROTECTION QUESTIONS & PE EXAM PROBLEMS | SUBSCRIBE NOW

Is this Sprinkler Obstructed by Light Fixture?

5/7/2019

9 Comments

 
In a residential dwelling unit of a high rise building, would a drum light fixture (7"h x 14"d) qualify as an obstruction?

It’s a concealed head in a residential unit of a senior living building.

The contractor – of course – doe not have exact dimensions because it wasn’t reflected on the plans and was added later as a lighting option and only caught by my inspectors during Rough-In. As it is installed, the head is a few inches from the fixture in some units and “a few feet” in others. They want to add a head on the other side of the light, approximately 3 feet -4 feet away citing NFPA 13 8.10.6.2.1.4.

I feel that the light, while an obstruction, doesn’t count as continuous nor does it meet the requirements of a baffle, so if they want to add another head it’d have to be at least 6 feet away to prevent cold solder.

Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe
9 Comments
Clifford Schulze
5/7/2019 11:02:48 am

NFPA defines obstructions as both continuous and non-continuous. Can you relocate the sprinkler head to meet the obstruction criteria, in this case 2'-6" - 3'-0" off the fixture?

Reply
Rob Stewart
5/7/2019 11:08:17 am

If a residential sprinkler head - it is 8' minimum distance between sprinkler heads

Reply
pari
5/7/2019 11:19:49 am

NFPA13 D Section 8.2.5.1.1 Pendent sprinklers shall be located at least 3 ft away from obstructions such as ceiling fans and light fixtures.
Section 8.2.5.1.3 where the sprinkler cannot be located 3 ft away from the obstruction, an additional sprinkler shall be located on the other side of the obstruction.

Reply
Clifford Schulze
5/7/2019 12:31:59 pm

He mentioned that this is a high rise building so 13D and 13R won't apply

Reply
PETE
5/7/2019 11:23:17 am

Echo what Clifford said. The inspector is correct. The scenario you described is a non-continuous obstruction to the discharge. Per §8.6.5.1.2 in NFPA 13, the sprinkler needs to either be spaced away from the obstruction based on the table. If you look at your concealed cut sheet and find that the deflector falls 1 1/2" out of the concealed head, you'd be 5 1/2" obstructed by the light (7"-1 1/2"). That would put your sprinkler 1'-6" to 2' away from the near edge of the light. That is to spray beneath it. The other option given under that section is to sprinkler on both sides of the light. Minimum spacing rules don't apply in this option because you're treating the obstruction like a wall. In other words, because of the obstruction the sprinklers won't spray on each other. The only requirement for the 2nd option is that the sprinklers are no more than the half distance of their maximum linear spacing from the center of the obstruction, again like it's a wall.

Reply
DaviD C
5/7/2019 02:48:58 pm

Pete well stated.

Just to expand on the cold soldering statement, if its treated as an obstruction or there is not the possibility of water from 1 head reaching the deflector of the other, it would not cold solder regardless of distance.

Cant tell you how many AHJ tried to state cold soldering when 1 head is 3 feet above another head in a different ceiling plane.

Reply
Jonathan Joseph
5/7/2019 12:25:43 pm

I would agree with Pari. You must be a minimum of 8 ' from the sprinkler or fixture in this case if you choose to add a sprinkler and keep the sprinkler that is obstructed.
I would try to re-locate if possible but it must be 3 feet away.
A light fixture cannot be considered a baffle because a tenant or owner can delete or change light fixtures at any time.

Reply
PETE
5/7/2019 12:45:07 pm

Anon did not state whether he was working per 13 or 13D, only that the space was a dwelling unit. Anon did state that the inspector objected to the placement per NFPA 13, so I assume it is an NFPA 13 job, not 13D.

Reply
Jonathan Joseph
5/7/2019 01:39:28 pm

It's a high-rise but the same rule applies to residential sprinklers.
NFPA 13 8.10.6.2.1.3(a) the four times rule or 3 feet away from light fixtures whichever works in the installers favor.

In this case the four times rule would be 4 foot 6 inches away and the obstruction table would be 4 foot to 4 foot 6 inches away if the deflector to obstruction vertical distance is 5 inches.




Leave a Reply.

    Jump to: Daily Posts
    Jump to: PE Problems
    Picture
    Why Sponsor?

    Free Signup

    Subscribe and learn something new each day:
    I'm Interested In:

    Community

    Thank You to Our Top
    ​October '20 Contributors!
    1. SK
    2. Franck
    3. Dan W.
    4. Jonathan ​5. Casey M.
    6. Sean
    7. Colin L.
    8. Mike
    9. Jonathan J
    ​10. Daniel G.


    Your Post

    SUBMIT A QUESTION

    The Toolkit

    Sprinkler Designer or Engineer?
    ​
    ​Get all of our tools, including the Sprinkler Database, Friction Loss Calculator, Fire Pump Analyzer and more:
    Picture
    FREE 30-DAY TRIAL
    GET THE TOOLKIT

    Filters

    All
    ABA
    ADA
    ASCE 7
    ASME A17.1
    Daily Discussion
    Design Documents
    Explosion Protection & Prevention
    Fire Detection And Alarm Systems
    Fire Dynamics
    Flammable & Combustible LIquids
    FM Global
    Human Behavior
    IBC
    IFC
    Information Sources For Analysis
    IRC
    Means Of Egress
    NFPA 1
    NFPA 10
    NFPA 101
    NFPA 11
    NFPA 110
    NFPA 12
    NFPA 13
    NFPA 13D
    NFPA 13R
    NFPA 14
    NFPA 15
    NFPA 17A
    NFPA 20
    NFPA 2001
    NFPA 214
    NFPA 22
    NFPA 24
    NFPA 25
    NFPA 291
    NFPA 30
    NFPA 400
    NFPA 415
    NFPA 497
    NFPA 5000
    NFPA 502
    NFPA 54
    NFPA 70
    NFPA 72
    NFPA 92
    NICET
    Passive Building Systems
    PE Prep Guide
    PE Prep Series
    PE Sample Problems
    Poll
    Smoke Management Systems
    Special Hazard Systems
    Types Of Analysis
    UFC 3 600 01
    UFC 3-600-01
    Updates
    Water Based Fire Suppression
    Weekly Exams


    Archives

    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    November 2016
    October 2016
    July 2016
    June 2016
    June 2015


    Daily
    Daily discussions are open-ended fire protection, fire alarm, and life safety questions submitted anonymously for the benefit of sharing expertise and learning from other perspectives. Anyone can submit a question here:
    SUBMIT A QUESTION

    Exam Prep

    Picture
    2020 PE Prep Guide​
    ​(Available Now!)
    Picture
    PE Prep Series
    ​(Available Now!)
    2020 PE Prep Series
    Current Leaderboard
    ​(Click to enlarge)
    Fire Protection PE Exam Prep

    PE Problems
    ​Visit July-October for daily Fire Protection PE Exam sample questions.

    Solutions are posted the day after posting.

    Comment with your solutions, questions or clarifications.

    Please note that questions posted are unofficial and in accordance with NCEES rules are intended to be similar to actual exam questions, not actual exam questions themselves.

    RSS Feed

Home - About - Blog - Contact - Exam Prep - Store
Picture
Copyright © 2020 MeyerFire, LLC
The views, opinions, and information found on this site represent solely the author shown and do not represent the opinions of any other party, nor does the presented material assume responsibility for its use. Fire protection and life safety systems constitute a critical component for public health and safety and you should consult with a licensed professional for proper design and code adherence. Some (not all) outbound links on this website, such as Amazon links, are affiliate-based where we receive a commission for orders placed elsewhere.
  • Blog
  • Daily
  • Exam Prep
    • CFPS Tools
    • NICET Tools
    • PE Forum & Errata
    • PE Problems
    • PE Store
    • PE Tools
    • PE Prep Series
  • TOOLS
    • TOOLKIT (FREE TRIAL)
    • *TOOLKIT (PURCHASE)
    • SUBMIT AN IDEA
    • BACKFLOW DATABASE*
    • CLEAN AGENT ESTIMATOR
    • CLOUD CEILING CALCULATOR
    • DOMESTIC DEMAND
    • FIRE PUMP ANALYZER
    • FIRE PUMP DATABASE*
    • FIRE FLOW CALCULATOR*
    • FRICTION LOSS CALCULATOR
    • HANGER SPACER
    • IBC TRANSLATOR*
    • K-FACTOR SELECTOR
    • NFPA 13 EDITION TRANSLATOR ('19 ONLY)
    • NFPA 13 EDITION TRANSLATOR ('99-'19)*
    • LIQUIDS ANALYZER*
    • OBSTRUCTION CALCULATOR
    • OBSTRUCTIONS AGAINST WALL*
    • PLUMBING FIXTURE COUNTS
    • REMOTE AREA ANALYZER
    • QUICK RESPONSE AREA REDUCTION
    • SPRINKLER DATABASE*
    • SPRINKLER FLOW*
    • TEST & DRAIN CALCULATOR
    • THRUST BLOCK CALCULATOR
    • TRAPEZE CALCULATOR
    • UNIT CONVERTER
    • VOLUME & COMPRESSOR CALCULATOR
    • WATER SUPPLY (US)
    • WATER SUPPLY (METRIC)
  • CODE CALLS
  • LOGIN
  • STORE
  • About