Fermentation Chamber...maybe

So after I put all the money into building this thing I would have been better off buying a chest freezer, but here's what I've got.

Big insulated box
Mini fridge
1.5" PVC pipe insulated inside of 3" PVC pipe going between fridge and box
CPU processor fan controlled by love controller

The plan started with the 'son-of-a-fermentation chamber', but I didn't want to change out ice, and I wanted something to fit 3 buckets or carboys. My wife stopped the idea of pulling the coils and compressor off the fridge, so I decided to pipe the fridge air to the chamber with a small fan. If it works, I'll have a fermentation chamber and a beer fridge. If it doesn't...it was a thought. Just turned on the fridge to see what happens to the chamber temp without the fan running, then we'll see what temp it can hold in there...I plan on putting in a return-air pipe back to the fridge as well.

I'd post pics but I'm unable to...updates to follow.

i'm pretty sure it'll work. look here, this is basically exactly what you're thinking about doing... Fermentation Cooler box construction - BrewBoard

yeah, pretty close to that...mine doesn't seem to work very well though. It only got down to 57, about 10 degrees below room temp. I'm thinking about covering the insulation in the box with plexiglass to create more of a barrier...anybody know if covering the insulation like that will make any difference?