×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Stairwell Exit Window Sprinkler Proctection?

Stairwell Exit Window Sprinkler Proctection?

Stairwell Exit Window Sprinkler Proctection?

(OP)
I have looked through NFPA 13 and cannot seem to find the answer. Designing an Elementary/High School, I believe the architect is looking at using glass on the exit/stairwells. We need to provide window sprinklers. If there are 5 sets of emergency stairwells, do you require to only flow one set of heads along with the hydraulic calculation/remote area? My gut is telling me this is the case. The only mention I see in NFPA 13 is dealing with exposure sprinklers for exterior walls.

Cheers... any help will do.

RE: Stairwell Exit Window Sprinkler Proctection?

Is the glazing serving as the fire-resistive assembly to separate the stair shaft from the remainder of the building? If so, NFPA 13 is not going to help you.

Is the exit enclosure on the exterior wall or interior wall? I ask because if this project is in the US, it makes a difference when applying the requirements in the 2006 International Building Code.

If you are seeking a design solution where the sprinklers protect the glazing and this design will be proposed as an alternative to the required fire-resistance rating of a wall assembly, the following is a design that has been accepted by a number of jurisdictions:

http://www.icc-es.org/reports/pdf_files/NES/NER516.pdf

 

RE: Stairwell Exit Window Sprinkler Proctection?

(OP)
Thanks Stookey.

The window in question is an interior wall, would typically be the window on the corridor side of the stairwell.

And yes the window makes up a fire rated wall. However the Archs. hate the tempered glass with the pretty wire mesh installed in them. hahaha. However the link did have the answer. Thanks.

I thought again that the window, if part of a fire rating, needed a head on both sides. Doesn't seem to be the case however.

Cheers.

RE: Stairwell Exit Window Sprinkler Proctection?

If you use Tyco WS sprinklers, they have to be installed a couple inches below the top of the glass.  Many architects do not like this arrangement.  Also, you can't have horizontal mullions when you use the WS sprinklers.

We have always provided standard spray sprinklers at 6' on center on both sides of the glass.  This is one of those - I was taught it that way and the guy before me and the guy before him, etc..was taught that way.  I am not sure if it is still allowed or correct.  I know the IBC talks about closely spaced sprinklers for atriums, but may not apply in this area.

Good luck!

Travis Mack
MFP Design, LLC
 

RE: Stairwell Exit Window Sprinkler Proctection?

(OP)
Stookey & Travis,

Yeah the link to the fancy window is very interesting.

Just another follow up question with regards to window sprinklers. I just can't seem to find much information in NFPA 13 dealing with them. The only references to windows I see in NFPA are marine applications and what the flow rate is desired from a window sprinkler.

If you have a building with multiple windows protected by window sprinklers, do you only need to flow one set along with a remote area hydraulic calc.?

I'm being told by a senior eng. that the window sprinklers need to be fed off of their own zone? I find myself wanting to disagree but cannot find any code material to back me up.

RE: Stairwell Exit Window Sprinkler Proctection?

Typically, window sprinklers are open so they need to be on their own system.

I have seen both the Tyco and the expensive glass proposed on a project.

The architect was enclosing a two storey elevator tower in glass.  We told him he had four options.  He could use the expensive glass.  He could use the Tyco option and have a row of sprinklers every 13 feet up the tower.  He could put a row of open window sprinklers at the top - which would require the AHJ buying off on it.  The option we liked was the fourth - get rid of the glass and make it a solid wall.

He seems to be leaning toward the third option We are awaiting the AHJ's opinion.

RE: Stairwell Exit Window Sprinkler Proctection?

(OP)
What is meant by an open sprinkler?  

And when you say open system does this mean have it's own supervised valve and flow switch, drain and site glass?

RE: Stairwell Exit Window Sprinkler Proctection?

Jeremiah:

He is referring to a deluge system that is for exposure protection.  In a deluge system, there is no fusible link in the sprinklers.  The deluge valve is either electrically or pneumatically activated to flow water from all heads (think Hollywood).

I don't have 13 in front of me now, but I believe the requirement is a minimum of 3 gpm / lineal foot.  So, if the heads are 6' on center, then you need 18 gpm as a minimum.

When I have sprinklers in this scenario, I just do multiple calculations.  Assuming the closely spaced sprinklers are not in the physically most remote area, I will calculate that area and size my system.  I then do another calculation for 1500 sq ft (or whatever your area) to include the closely spaced sprinklers.  It doesn't make sense that if I have 50k sq ft and closely spaced sprinklers near the system supply that the entire system should be "punished" for a row of closely spaced sprinklers.

I hope that makes sense.

Travis Mack
MFP Design, LLC
 

RE: Stairwell Exit Window Sprinkler Proctection?

have not seen window protection in a long time, but last one I saw was closed head designed for window protection.

not an engineer, but to me you need to first look at the manufacuter sheet for the head to be used.

http://www.icc-es.org/reports/pdf_files/NES/NER516.pdf

http://www.obc.mah.gov.on.ca/Asset181.aspx




try this::::  http://www.tyco-fire.com/index.php?P=show&BK=Search&id=TFP620_07_2005&CP=4


just one person's opionion: http://www.fireglass.com/press-room/articles/sprinklers.aspx

RE: Stairwell Exit Window Sprinkler Proctection?

"I'm being told by a senior eng. that the window sprinklers need to be fed off of their own zone? I find myself wanting to disagree but cannot find any code material to back me up."

Establishing a separate zone would not get you around the requirement in NFPA 13 that the additional flow from water curtain heads in a remote area be accounted for.

I would say nice try, but no sale.

And dare I go here again, why Tyco window spriklers????  Why not use standard spray pendent, semi recessed or concealed heads placed accordingly?
 

RE: Stairwell Exit Window Sprinkler Proctection?

I believe the reason you cannot use a standard spray sprinklers in this case is that the window assembly is not rated the same as the solid wall of the stairwell - so you have to provide special fire suppression to make it so.

That is how I understand these situations.

 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources