I had a crazy idea to relocate the compressor and coil from my fridge to the mechanical room in the basement directly below it. It would cut down on noise and should make the fridge more efficient because it wouldn't be dumping its heat under itself. Once the heat is dumped in the mechanical room, a heat exchanger around the pipe to the hot water heater would have to help a bit. Even in the summer water out of the ground is pretty cold and anything to take the chill off would be a bonus.

Basically what I thought. I googled and saw a few "fridge harvesting papers" I should read (or you ? .. ?)

  - http://www.irdindia.in/journal_ijmer/pdf/vol4_iss1/9.pdf
  - https://info.ornl.gov/sites/publications/files/pub31294.pdf
  - https://www.acoustics.asn.au/conference_proceedings/AAS2009/papers/p28.pdf