I can't believe people still ask this question after 10 years of commercial water-cooling 
It might work for a while but Fridges are not designed to deal with a continual heat load. You will burn out the compressor in short order. There's also condensation to deal with on the cpu, piping etc. More hassle for little gain.

It might work for a while but Fridges are not designed to deal with a continual heat load. You will burn out the compressor in short order. There's also condensation to deal with on the cpu, piping etc. More hassle for little gain.