ESFR Dry pendent sprinklers and ceiling-level obstructions

[skdesigner]

I have a question with regards to the ESFR dry pendent 'box-in-a-box' freezer installation. How do you handle the large ceiling-hung condensing units that are present in basically every large cold storage freezer / cooler? Do you provide some kind of a supplemental system below the units? I see that the new antifreeze solutions are listed for storage occupancies, but specifically exclude ESFR systems.

We have a large cold storage freezer where the mechanical consultant has specified ESFR dry pendents, but provided no direction on how to address the condensing units. I'm sure I'm not the first to run into this issue, and I am curious how others have dealt with it.

 

[cdafd]

So about how many sq ft is the protected freezer??

And how high is the storage?

 

[skdesigner]

Call it 20,000 sq. ft. or so. 22' storage under a 27' deck. With ESFR dry pendent sprinklers seeming like such a popular option, I'm mostly just curious how the condensing units are being treated from an obstruction perspective.

 

[TravisMack]

It's been a while, but if I recall correctly, the condensing units I dealt with were <24" in width. As such, we didn't have to put sprinkler below. Again, it's been awhile so I may be fuzzy on that. I would just kick it back to the EOR on this one. I often tell people that a building must be built around an ESFR system. You can't always build an ESFR system into any structure. If they couldn't get the proper sized units, then it goes to standard sprinklers and a dry system.

Travis Mack, SET, CWBSP, RME-G, CFPS
MFP Design, a Ferguson Enterprise

http://www.mfpdesign.com

 

[skdesigner]

Thanks, that was definitely our plan. Like I said, I was more just curious how they were being addressed, since they are present in basically ever freezer or cooler. I'm struggling to figure out how they are so popular if the answer is always, ESFR doesn't work here, use a dry system.