Constructing Your Cold Space by Chris Savage

Constructing Your Cold Space


Chris Savage


Here at Carlson & Stewart Refrigeration we get the opportunity to visit with a lot of great people who have a lot going on.  I had the opportunity this week to visit with a customer who was working on a project that would require construction of a new cold space.  Here at Carlson & Stewart Refrigeration, we are not construction experts, but we have certainly been around a lot of cold space construction.

There are a lot of considerations that need to be made when building a cold space, and like I mentioned, I am not an expert.  Which is my first point.  Make sure you are talking to someone who is an expert for cold space construction.  Believe me when I say that not just any builder knows how to build a cold space.

One thing that you need to make sure to consider and that is moisture.  In any construction, moisture is your number one enemy, so I’ve heard and I believe.  This is even doubly so in cold space construction.  This is why a vapor barrier is so important. 

Moisture travels just like temperature, always from warm to cold.  I have even been told that moisture travels faster than temperature.  So when building a cold space wall/ceiling/floor you are trying to slow the speed of heat and moisture transfer enough to keep things under control.  The type and thickness of the insulation will determine the speed of temperature (heat) transfer but the insulation has very little effect on the moisture transfer.

Think about what happens to the outside of your cold beverage on a warm summer day.  Moisture collects on the outside of the container.  The moisture is coming out of the warm air and condensing on the surface of the cold container.  So if you don’t stop the warm moist air from coming in contact with the cold surfaces in a cold space, you will get condensation.

I have seen cold rooms built using 2x4 and even 2x6 wood construction and then filled with spray foam type insulation.  The inside surface has been covered with sheets of white bead board, which stops moisture migration.  Statements are made that the insulation is “closed cell” and so it should stop moisture migration also.  So it seems like this should work, doesn’t it?  It doesn’t.

Again, I am not an expert but I think this is why.  First of all, just because the insulation is called “closed cell” does not mean it will stop moisture.  I have seen plenty of insulation saturated with moisture.  Also, wood is not a great vapor barrier.  Wood will absorb and transfer moisture.  So the moisture is able to travel through the insulation and the wood and then it reaches the cold, backside surface of the bead board, which is a good vapor barrier and there it condenses, just like on the outside of your cold beverage container.

So my whole point to this little article is the phrase that I have always heard when constructing a cold space, “vapor barrier on the warm side.”  So when building a cold space, you have got to have a good vapor barrier on the outside surface.  This is why insulated metal wall panels are such a good option when building cold space.  The metal skin is a great vapor barrier.