Decided to go ahead and build a fermentation chamber while the family is out of town. I had two of the small mini fridges given to me. I also had a couple of computer fans laying around that I mounted to the cooling units to blow into the chamber. The thought is to have two zones if needed. Went with two layers of .75 inch r-max insulation. The only thing I'm missing now is the temp controller which my wife is getting me for my birthday. It's already down to 33 F.