I am pretty sure that would hold your carboy, but it is not a very conducive shape as it will only hold one due to the lack of side-by-side space. You can use a temp controller successfully on a fridge but they are really better for freezers. If you want to lager you need to make sure your fridge can get down to that temp in the first place (it should, but it depends on the age of it) and if it does, the temp control unit will work fine. I really recommend not getting the redbull cooler, your money is much better used going on craiglist and buying a used chest freezer. I bought one and I can fit 3 carboys in it, lager in it, run 6 kegs....and it was 80 bucks.