Stairwell Exit Window Sprinkler Proctection? 1

[Jeremiah187]

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.

 

[stookeyfpe]

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

 

[Jeremiah187]

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.

 

[TravisMack]

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

 

[stookeyfpe]

Jeremiah,

If the architect doesn't like the aesthetics of the design they always have this as an option:

http://www.safti.com/factsheets/SuperLite II-XL 60.pdf

Just tell the client to open the checkbook.

 

[Jeremiah187]

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.

 

[PEDARRIN2]

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.

 

[Jeremiah187]

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?

 

[TravisMack]

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

 

[cdafd]

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

 

[firepe]

"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?

 

[PEDARRIN2]

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.