Inrack Calcs with a Grid Overhead system

[majesticphil]

So calculating a InRack System with the Ceiling having an existing grid system. The overhead system will need to be modified to make the calcs work. The contractor only wants to modify the portion of the grid directly over the racks. Is that acceptable?

When you run a calc like this do you calculate the most hydraulically remote part of the grid to balance with the inrack system or do you only calculate the part of the grid directly over and within 15' of the inrack system?

Thanks in advance for your help.

 

[TravisMack]

If there is a big difference calculate the overhead system that is directly over the racks. If the overhead is 40k sq ft and you only have 5k sq ft of racks that are right by the riser, no need to flow the overhead sprinklers that are no where near the racks.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[Sdpaddler50]

Good question. I have had this occur as well. It has been awhile, but as TM notes, I only asked the contractor to calc the overhead over the racks, and 20 ft beyond. As long the client is going to maintain their storage in that particular footprint area, it makes sense. The problem I see, is 5 years later, when everyone forgets about the situation and the racks get moved, but that is for another thread.

Since you need to modify the ceiling anyway, did you look at ceiling only ESFR/CMSA options, to avoid the in-racks? You would still need a draft curtain to separate QR from SR heads at the ceiling, but it may be a wash money wise, and you avoid the dreaded in-racks that most operators don't want.