Cold Storage Design 3

[Elindio1]

I'm verifiyng if it is possible to install a cold storage room inside an existing warehouse over an existing 6" slab. The room is to operate at 2 C / 35.6 F. The cold room provided says that no demolition of the slab is required but I think there is going to be some heaving or swelling in the slab so I will need to install some type of heating system to the slab. Is there a "treshhold" temperature below which heaving will occur (0 C)? Or in this case the temperature is not that low so no heaving could be expected?

Thanks!

 

[rowingengineer]

Cold storage in an existing building is interesting. Generally I wouldn't get concerned about frosting of the ground until the cold room temp range is near or below 0c. I assume your cold room has a range (2-8?) so your cold room probably does not need heating, however this would also depend on size of the cold room (if it is huge you would review this as there will be a temp grad across the room). Note I would always design for the range as I am conservative and believe that if it can go below 0 then it will in time. If you are really concerned I would provided a heat blanket and not touch the existing slab.
Just a few questions:
Do you have a wearing slab on insulation? What is the thickness of both?
Are you in a high humidity area?



When in doubt, just take the next small step.

 

[Elindio1]

Well, Rowengineer, the cold storage will be around 60' x 80'. There is no wearing slab over insulation. It is only a 6" slab over soil.
On the humidity, the area is a warehouse that has a 70% RH at least. But normally the area or geographical area the warehouse is very humid.
Thanks for the information!

 

[H57]

Typically for coolers there is not a need for underfloor insulation or heat. I would not be concerned if it is 35 degrees.

 

[spats]

If you don't at least have perimeter underslab insulation in the cooler, and the slab is continuous through to the warm side of the wall, the slab outside the cooler will sweat like crazy. This is a liability problem in the very least, because people will slip and bust their butt!

Also, I don't know how you could properly seal the base of the cooler wall at the slab. Normally, the cooler wall needs to seal to the underslab insulation. I suggest a 4' width of perimeter underslab insulation in the cooler.

 

[civilperson]

The floor neees insulation for the reasons given by spats and for energy savings.

 

[lkjh345]

I would seriously consider removing the existing slab, putting 4" of rigid insulation down, and casting a new slab for the cold storage portion of the building.

As spats points out, normally, the insulated walls are connected to the underslab insulation. Also, it is unlikely that the vapor barrier below the existing slab was place and sealed correctly to prevent vapor transmission inside the cold storage building.

It will be difficult, and over the long run expensive, to keep the inside of the building cold if the slab is continous from outside of the enclosure to the inside.

Vapor barriers and insulation in cold starage buildings is a whole subject unto itself.

 

[rowingengineer]

Elindio1,
As the others have quite rightly mentioned the cold room detail you are suggesting will have some issues with losses, and surrounding slabs, however this has been done before. @2deg I personally would be suggesting an insulated floor on top of the existing floor just because of losses through the ground and slab.


When in doubt, just take the next small step.