Sprinkler design for shopping mall atrium space with high ceiling

[MEP.Learner]

Hi Engineers,

I have a situation where there is a shopping mall atrium with 25m ceiling height, atrium diameter is about 30m diameter on plan view.
So the question is what kind of sprinkler can be adopted for this atrium protection as in BS EN code mention that sprinkler more than 18m is not efficient.

Solution with Deluge sprinkler.
If deluge sprinkler / open head sprinkler to be used, what K factor and what type / what is the required spec of the sprinkler to be used.
Can normal OH3 5.6K factor (as per BS EN) can be used? Any concern that the water from this sprinkler not able to reach the fire source?

Any online reference or article that i can refer to design for this case?

My question does not specifically need to be in reference to NFPA. Any BS EN code/ LPC reference to solve this issue will help too.
Is there any fire related discussion topic other under than this sub forum “NFPA”?

Thanks.

 

[skdesigner]

FM Global Datasheet 3-26 Table 2a provides protection options for wet sprinkler systems under ceiling heights up to 30m. The downside is, of course, that you're limited to using a sprinkler with a 25.2 K factor.

 

[MEP.Learner]

I believe FM global data sheet is referring to high pile racked storage protection? Which if we were to use K 25.2 sprinkler will be way over size? This will result in high flowrate pump, big storage tank size requirement.

 

[TravisMack]

Actually, if you read the title of the datasheet you will see it is for NON-storage. The FM datasheet is about getting a large droplet size when you are significantly elevated above the floor.

Yes, you will have a large demand. I believe the FM criteria is (12) K25 sprinklers at 7 psi. This is about 800 gpm minimum. If you don't want to do that, then find another way to deal with the higher elevation. This is just one item that has some documentation for what is proposed.

Best of luck.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

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[skdesigner]

Thanks Travis, you beat me to it.

Table 2a clearly states that HC-1, HC-2 and HC-3 all need to use the (12) 25.2K @ 7 psi design criteria when the ceiling is up to 100'-0 (30m).

The second example occupancy type in the HC-1 category is Atriums.

I never said it wasn't oversized, or the most cost effective way to proceed... just that it exists as an option.

 

[crb7]

hi
i guess you have to use CMSA sprinklers which is designed for high ceilings.