What to use as insulation for built-in cooler?

jtexas!

What do you mean? I do hope you are OK!!!

Pretty much any good 'production' fire-retardant insulation will do.

When I was fitting big luxury sailing yachts for a major international yacht builder in the '80s (who also went pear-shape) ... we always had a standard way of thinking with regard to cooler units.

The main thing is make it top loading. (Cold air behaves a bit like water in a fish tank, it is heavy and gravitates to the bottom: if you were to open the front, well, water all over the cabin sole, to say nothing of the fish.) And this lost cold air is then immediately replaced with new, warm air.

The heat in that new air must then be 'pumped' out, using limited on-board resources (diesel from the tank, basically).

Fine, I suppose most people are prepared to accept, in a land-based 'domestic' situation where energy supplies and resources appear to them to be infinite and infinitely affordable, but not sound thinking. Another question of course.

But not on a boat, with very finite resources.

So make the chiller top-loading, insulate the whole thing (even the lids if you can) with up to three inches of insulation foam and the only heat that will get in there will be what you put in. (Eg: warm beer).

Take care and stay cool.

And good luck.

-|--)

I think fiberglass expands and fills cracks and crevices more. It's hard to cut styrofoam so precisely that there aren't leaks somewhere. I'm pretty sure the fiberglass is less expensive, too. I don't know what your criteria of "best insulation" is, I think code where I am is R-21 in the walls, and R-40 (or thereabouts) for the ceiling, but insulation is one of those things where the more, the better. Right off the bat, if this is a typical metal building, it's probably sitting on an uninsulated concrete slab. Those are notorious for sucking heat away from a building, although it probably helps during air conditioning weather. If you wanted to put foam to some good use, putting some on the floor might be a good place (make sure it's the pink or blue stuff suitable for direct burial, otherwise, moisture will negate the insulation effect). EDIT: The link below tells about foam insulations. It says foam is more expensive. Many types have moisture issues. If space is tight it's often used. Yes, R-value is about 3-4 times greater per inch than fiberglass, but it still costs more.

I found my beer stayed cooler propped against the seacocks in the heads than in the insulated so-called coldbox just above the engine.

So my Mk2 coldbox has a coldplate cooled by the raw cooling water on it's way to the engine, augmented by one of those solid-state (Peltier) coolers. Nothing like the performance of a proper compressor refrigerator, but cheaper and better than nothing.

I think I used pink foam and silvered bubble-wrap.

Sorry to hear that JT. Both my dad and brother flew many years ago for them, and it has changed drastically since then.

As for the foam, pink foam works well. I have used it but I also once used a two part foam in between a shell of starboard. Once it was done expanding and I trimmed the excess it was a great cooler and very rigid. Good luck with everything.

find a cooler that will

fit within