Window Sprinklers , Water curtains & Ceiling Sprinkler Calc

[RedlineFP]

Hello Forum,

I am designing a Community Recreation Center, Two levels and about 20,000 Sq Ft Area.
There is an area with exposed ceiling structure (21' high) having an vertical opening to the floor above which requires water curtain as per 8.15.4.
In the same area one side big glass wall seeing thru the skating rink. My confusion is that do I have to calculate all 3 together (water curtain , Window sprinklers & ceining level sprinklers - 1500sq ft) ?
I have to size a fire pump based on the highest demand. If I calculate all 3 levels together it comes up with insane flow & pressure requirement and leaves tonnes of safety for rest of my calculations. NFPA doesn't say whether I have to calculate all 3 together but at the same time it doesn't allow the opposite either. My thought process is that I should keep the higher demanding areas from the two combinations calcs, Either Water curtain with 1500 Sq ft calc or window sprinklers with 1500 Sq ft calc. But I am not an engineer so I don't back myself up to make such calls.

Will appreciate any help from the forum.

Thanks & regards,
RedlineFP

 

[TravisMack]

My opinion is that you have to take the most hydraulically demanding area. If you can get a 1500 sq ft area that has all 3 in that area, then you have to include them all in the calcs as it is the most demanding area.

However, I am no PE (yet), but I often take a conservative approach on those issues.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

"Follow" us at

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[cdafd]

What is the size of the vertical opening ?

What is the set up for glass protection? And I guess the ahj has accepted this in place of rated opening protection?

 

[RedlineFP]

Size of the opening is < 1000 Sq ft. , Window Sprinklers were spec'ed by the Architect to maintain the rating of the wall.
looking at the all steel construction and the building being a rec. center, I believed that calc'ing all 3 together was overkill. Wanted to make sure that my final product don't look stupid with calcs showing 80 psi safety in other remote areas and an Over sized Pump for the building.

Thanks for your reply Travis & cdafd.

 

[TravisMack]

Yeah, unfortunately, they just have three items that drive your design demand right next to each other, so you have to size that pump for all three. It does seem like overkill, but that is what you are up against.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

"Follow" us at

https://www.facebook.com/pages/MFP-Design-LLC/92218417692

 

[cdafd]

Ibc 2012

You can't but you can


703.4 Automatic sprinklers.
Under the prescriptive fire-resistance requirements of the International Building Code, the fire-resistance rating of a building element, component or assembly shall be established without the use of automatic sprinklers or any other fire suppression system being incorporated as part of the assembly tested in accordance with the fire exposure, procedures, and acceptance criteria specified in ASTM E 119 or UL 263. However, this section shall not prohibit or limit the duties and powers of the building official allowed by Sections 104.10 and 104.11.

 

[stookeyfpe]

Redline never stated the jurisdiction so we shouldn't speculate CDA. This is a forum, not a plan check.

 

[Duwe6]

Ah, yes -- AHJ. If the Authority Having Jurisdiction says 'yes', then you meet NFPA and are OK. Even if you meet NFPA and the AHJ says 'no', you are wrong. Period.
Anytime you get into a 'grey area', or an odd-ball one like Redline has hit, asking the AHJ is very prudent. Might save you and your client a bunch of engineering time.