Fermentation chamber from mini upright freezer

So, I recently became the owner of a ~5 cu. ft. mini upright freezer, and am looking to build a fermentation chamber as the cooling coils are actually the shelves themselves. I have a good idea of the work that would be required to do this (basically build an insulated box that attaches to the freezer opening, rig up the temperature controller, seal well), but I'm contemplating how I'm going to go about building the box / collar.

I've seen several fermentation chambers where people have built a box out of plywood and 2x4's and then lining with foam/insulation to maintain temps. Usually there is an air gap between the exterior of the box and the foam to provide extra insulation.

Long story short, my question is this - would it be totally inefficient to just build the foam box around the upright freezer? I know that the SOF chiller is constructed of just foam, so I know that it would work, but am I likely to lose a lot of cold air without building a wooden frame around the foam (and thus losing the air gap in between the walls)? Has anyone simply made a foam housing around a mini-fridge / freezer with good success? It would certainly cut out a lot of labor and some costs if it works.. but I don't want to run the crap out of the freezer if it's totally inefficient.

Thoughts?

 

The wood doesn't necessarily help with cooling or efficiency, but it does give the foam some protection. Without the wood, I would be afraid of punching a hole through the box or dinging the crap out of it. You can certainly do it, just be aware that its a little more fragile.

 

In that case, I might just build a base for the bottom (where carboys would sit) from 2x4's and plywood, then apply the foam and some waterproof layer, but keep the sides and top simply foam. I don't plan on moving it around , but I can see hitting the sides occasionally while jockeying carboys around.

 

Been done and this article is kinda a how to with pictures.

 

Not sure how that answers the question.. though that's a pretty bad ass build. I'm working with an upright freezer (the link deals with a chest freezer) and my question is whether building a collar out of just foam board (instead of the typical wood frame insulated with foam board) will work. If it's a structural integrity/aesthetic thing (and not insulation performance) then I probably won't waste the time and energy in building an entire wood frame - I'll just build a wooden base and assemble a foam board box around that.

Still, a nice build, thanks for sharing the link.

 

Sorry I saw upright and translated that to chest - my bad