ESFR Obstructions

[WallyFP]

NFPA 13-2007 Tale 8.12.5.1.1 provides guidance for obstructions below ESFR's but I'm not clear where the following would fall in this? Any guidance would be appreciated.

I've got several 11-inch wide x 8-ft. flourescent light fixtures that are located 32-inches below the pendent ESFR deflectors. The horizontal distance from the sprinkler to the edge of the fixture varies from less than 1-ft. to 5-ft. The fixtures are centered in aisles and are within 12-inches from the top of storage level.

FM 2-2 2.4.5.3 states that obstructions greater than 36-in. below deflector won't disrupt discharge pattern and are not a problem unless directly over a flue space. Does NFPA provide similar guidance as to how far below defector something like the above light fixture would need to be to not be considered an obstruction?

I'm not sure what the options are but this seems like it is a problem.

Any thoughts?

 

[LCREP]

see NFPA 13, 07 8.12.5.3.1 (3)

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Fire Sprinklers Save Firefighters’ Lives Too!

 

[WallyFP]

Thanks LCREP.

That helps for most cases but one area I'm still a little foggy on.....

If less than the 12-inches horizontally, NFPA seem silent as to how far below before it is not a obstruction (assuming it is less than 2-ft. wide).

In other words, as I understand it, a light as described located 8-ft. below an ESFR head is not considered an obstruction. At 30-inches below, it is. Does NFPA provide guidance as to what point (how far below) it is no longer an obstruction?

It is easier to lower the lights to 36-inches below (or whatever) the deflector than move them 12-inches horizontally but I want to be clear on NFPA guidelines.

Thank you.

 

[LCREP]

Since a minimum of 36" must be between stock and sprinklers, I would say, the 36" is the number to answer your question.

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Fire Sprinklers Save Firefighters’ Lives Too!

 

[WallyFP]

Makes sense!!

Thanks.