fermentation chamber sizing

[gregkeller]

so I got my hands on a dorm fridge, something in the 4 cubic foot range. The kind with the cooling element as the base of the freezer. I'm not able to modify the fridge other than things that can be returned to stock. So i can pull the door off, remove the door liner with can racks, etc. When I do that I can fit an ale pale in it, but nothing else. I want to build a fermentation chamber around it so i can fit a few fermenters in it. I'm planning to build a box out of plywood and expanded foam insulation.

My question is how big can i make it, and still effectively be able to keep it at a useable temperature. I'd love to be able to do lagers in it, but i don't have a fridge to dedicate to lagering, and I also wouldn't want to tie up the fermentation fridge for 4-6 weeks at lagering temps.

So lets say i want it to be able to do ales, cold crashing would be nice also. It's going to be in my basement that maintains a temp of 59 in the winter, and not sure about summer as i've only been in the house for one year, and didn't brew last summer. But it's may and the temp is about 64. So i'm not picturing the need for tons of cooling/heating power. I also don't want to build it so big that the compressor is running all the time and burns out in 3 months.

So could i expand it to hold 4-5 ale pales and be fine?

 

[hopsalot]

How big is the compressor? I think how you insulate it would determine the size. 4 cubic feet seems large for a dorm fridge