Those little fridges will not work to cool a pc.
The reason being those things like lasers have a duty cycle, they are not meant to run 24/7. they come on for a few min then off.
If you ran a pc inside one it would not be able to keep up, so one of two things will happen.
The fridge will fail to cool and your cpu will fry or the fridge will try to cool but soon start to fail
The second option might take it a day or a week. Mine took about 3.5 days and was having thermal shutdown on the 3rd day.
As i have used this system of a fish tank and made my own liquid cooling system out of a pump and a cars heater coil and 2 small fans.
If you want the best cooling system, i would recommend using a phase change cooling system.
I got a margarita machine of ebay and modded it for my cpu and it works great.
They are meant to run for very long periods of time even it hot summer days.
i was even able to mod it back for the winter because i had some parties maybe i will post some pics if i put my cpu back to it.