Hi PhilB,
My B36 2002 had a retrofitted cooling system for the refrigerator where this was fitted as part of the deal before I bought the boat secondhand. I think, from looking at the way the furniture within the boat was put together, that what was described as a "cool box" by the seller had started off as a fully working refrigerator that had thrown its hand in at some time in the past and which had not been reinstated until it became part of the deal to purchase the boat.
The cooling unit subsequently fitted was an Indel Webasto Marine Isotherm unit, namely their Compact Classic model which consisted of a flat plate evaporator, a thermostat and a Danfoss BD35 compressor.
The compressor was mounted within the space under the port side settee within the main cabin, it was wired to the main distribution board to the switch marked with three little stars, while the tube from the evaporator passed through a small, presumably existing hole located in the forward face of the cool box, and then through the woodwork to the area behind the settee back rest. It then passed down through another hole in the horizontal woodwork forming the base of the settee seat and into the area where the compressor is located. The end of the tube from the evaporator separates into two pipes each with self sealing connectors on the ends to retain the refrigerant gas within the evaporator. These connect to the same type of fitting on the compressor which presumably also contains R134a refrigerant. As the connections are tightened the pathway for the refrigerant opens to allow it to be circulated between the compressor and the evaporator.
The isotherm refrigeration units are not the most economically priced, but the one I had worked well for four and a half years until chafe where the evaporator pipe passed through the hole in the settee base caused the pipe to leak with consequent loss of refrigerant. This was repaired by a local refrigeration firm after I'd taken the evaporator and compressor and associated pipework off the boat, though I have no idea how long the repair will last. In order to prevent further chafe after refitting the system, I've put some domestic water pipe foam insulation around the the pipe where it passes through holes and rammed it in to the holes so hopefully there will be no more chafe. The system used to work well enough to turn the entire cool box into a freezer, and while I've not used it yet since the repair other than to test it, it did seem to be working rather well again. The repair cost was around £180 which I thought was a bit steep, but it was less than the cost of a new unit.
