I think the best solution I saw was on Dashew's website. He uses a small isolated compartment of his water
tank into which he fits a keel cooler
. The water
tank disperses heat through the hull
and because it is separate can be kept full always. There is no hole in the hull
and no fouling or drag losses or galvanic corrosion
worries or requirement to replace zincs. So he gets the full benefit of the lowest possible energy use refrigeration
, no fan noise
and puts most of the refrigeration
heat out of the boat.
Modern keel cooler
units have factory fitted filters now and I don't think they will block the system like they used too. My two 15 year old units have never failed for what it is worth.