Wow! So much great information ... it must be totally overwhelming for somebody who just wants to get a cold
beer...however you can see how much time people(cruisers) spend to solve these problems.
Just to add a couple of thoughts that weren't obvious to me when I started cruising ...
Non-sealed insulation will absorb water and become totally useless regardless of how much there is... so NEW insulation MUST be sealed water and air tight inside and out. The easiest way is
fiberglass sheet and
epoxy or
fiberglass tabbing. The stainless is a huge problem if it can transmit cold to the outside but not if it is just a liner inside the unit. Realize that you will have to defrost and clean them periodically. Water drains can be very inefficient.
More insulation is always best if you can do it. I spent a lot of time looking for refrigeration insulation but the closed cell
sheets from building supply stores works great. Smaller boxes is better too to a point. Efficient refrigeration units are amazing! I once had a cool blue system and am a big fan!
Engine driven systems may be efficient too but who wants to run the
engine at
anchor EVERY day and what do you do when you
haul out?
Why did you remove the old system? I once removed a system and then someone pointed out that it probably just needed a thermostat. It's been working great for 14 years since I replaced the thermostat.
While it may not feel too hot in the
Bahamas or
Caribbean when you are in the water it could easily be 110 in the boat during the day. For air cooled the
compressor location is important and hopefully that's not in the engine compartment. Even in the
cabin its going to run a lot. That's why water cooled may be desirable but again how is that going to
work hauled out? Many cool by recirculating fresh water from and to
tanks. Of course, hot
weather is when you will want that cold
beer etc. so don't plan on a frig that runs all of the time in moderate conditions because it will not be able to keep it cold when the
weather is hot.
No matter how little you have to run the engine or
generator it will be annoying so learn about
solar. The best
solar system is twice the size the need. Seriously, all these budgets are great but really they are usually best case and things happen so you need multiple and oversize capacity. Also they
work much better when the
mast and boom are not shading them. You can buy a lot of solar for what a slightly more efficient replacement frig/freezer system will cost. Best of all it will work great when you are hauled out or off the boat. You will need some backup for when you get multiple days of rain but that is unusual in the
Bahamas.
Wind generators are useless in the
Caribbean when you
anchor behind mountains. While they generally work well in the Bahamas when it does blow...but it may not blow for days too.