Thanks Bob. Very helpful. Now I understand the basics of the Peltier module.
I have gears turning and am trying to see this in a practical application. Let me explain. I do a lot of blues. After draining, hooping, etc, the blue mold needs a few/several days to kick in. Room temp at 72-73F is too warm, and cave temp at 52F is definitely too cold. So, I put my blues in ripening boxes and incubate in a large milk cooler with a digital controller set at 62F. Works perfectly, but it would be really nice to reduce my electric load, and free up the milk cooler for other refrigeration needs - like actual milk.
I am familiar with the 12v Peltier drink coolers. So, what I am thinking is a super insulated (4" foam) closet sized box, say 4'w x 3'd x 5'h (60 cubic feet). Or maybe an old chest freezer. My thermodynamics is a little rusty, so how many of these would it take to go from ambient temp of 72-73F to the 60-62F that I want for my blues? If the TEC is around 12w, then it seems like it would take around 11 units to reach the 140w found in the dorm fridge. However, I only need to get down to 60F so the load is actually less. I am finding units on ebay that claim 136 watts for just $9. Is that an actual possibility, to use just one of these to cool a dorm refrigerator? Are these things waterproof? Seems like heat sinks on both the hot and cold sides would increase efficiency.
The 12v supply to the Peltier can always be controlled by an external temperature controller with a thermocouple.
REVISION: I actually just found a 400w unit on ebay.