I just mated a mini fridge to my existing fermentation chamber. I had been using frozen jugs of water, and now I have control. It is a 2'x3'x4' box with 2" closed cell foam insulation throughout. I just pulled one panel off the end, and the fridge fit quite nicely into the opening. I built a platform to hold the fridge off the floor, and I plan to finish it up with a magnetic seal like the one on the door. Right now it's controlled with a timer, and I'm still figuring out the right amount of time to let it run, but in the future, I plan to install a proper thermostat.