Lots of comments, but little advice
First - for reduced power consumption you need 6 inches of insulation - and make sure you get the right stuff, cause there is foam and insulation foam.
Second - again to reduce power consumption, it needs to be top opening, cause a door opening lets too much cold out.
third - the type of cooling
system will depend on how you make your electricity onboard. If you regularly run the engine
to get electricity, the best bet is a holding plate - this runs constantly when the main power is on, and builds up a big lump of ice to keep the system cool when main power is off.
- if you use solar power, then an evaporator and a thermostat is the way ahead. this uses a little power, but frequently.
fourth - how do you cool the condensate (i.e. the stuff that goes into the holding plate/evaporator) two ways, air cooling or water cooling.
air cooling - depends on a good supply of cooler air that you can duct to the right place. It also helps if the ambient temperature is cool. It needs extra power to drive the cooling fan.
water cooling - two types one sucks sea water up and pumps it through cooling chamber - trouble is the pump
uses power and crustaceans like the inlet and tend to block it. There is a fresh water variant of this that has cooling pipes on the outside of the hull
, but it still needs to be pumped seperately. There is a third variant that uses a bronze
block on the outside of the hull
. The condensate itself is pumped through this as a natural part of the refrigrant cycle, thus no extra pump
To the best of my knowledge all the best of these use a danfoss compressor
It is possible to purchase a cool box that you can transfer into your car etc, that has a danfoss compressor
, but these are expensive ($800)
A good system with good 6" insulation even in West Indies, will use about 35-60 amphrs depending on size and how often you put stuff into it.
It is possible to make a freezer
section using this, then add a small hole in a bulkhead between a freezer
section with the evaporator plus a computer fan to create a fridge as well.