On Thu, 03 Jul 2014 19:53:15 -0400, "Sir Gregory Hall, Esq."
wrote:

On Fri, 04 Jul 2014 06:36:53 +0700, wrote:

On Wed, 02 Jul 2014 19:58:42 -0400, "Sir Gregory Hall, Esq."
wrote:

On Wed, 02 Jul 2014 17:16:27 -0400, Wayne.B
wrote:

The inefficiencies of converting 12 volts to 110 are more than
compensated by the quietness of not running the generator
continuously. The lifespan of the generator is also greatly
increased and we are not tied to a dock with shorepower like most
motor yachts in our size range. The diesel fuel that the generator
does use for battery charging is a drop in the bucket compared to the
main engines, and when we are underway the engine alternators keep the
inverter batts charged at almost no cost at all. For boats that
already have propane for cooking there may be some advantages to also
using it for refrigeration but I prefer to have no propane on the boat
for safety reasons. I also like the convenience of having a single
fuel boat. Down in the Caribbean people from the US are always
juggling propane adapters to use the European butane fittings that are
commonly available.

What's the price of diesel *down island*? I've heard it isn't
cheap. I've heard some places it might be around ten bucks a
gallon. Propane, on the other hand, is generally much cheaper
than that per BTU equivalent

FYI, you don't get something for nothing. It might seem like the
alternators charging a low battery bank don't cause the main
engines to burn much more diesel but they do.

As for being quiet and not running a dedicated generator that's
a good thing but when using propane to refrigerate there is no
noise at all, ever. No fumes either from a generator or the
main engines charging up a battery bank so an inverter can do
its thing and thus waste about 10% of the energy.

Don't most diesel generators such as a typical 8KW version produce
alternating current? If so, think what you do when generating using
it. It generates 120VAC which is then transformed to 12volt DC via
a battery charger to charge the batteries (10% loss). Then you turn
around and invert it back to 120VAC to run the freezer (another 10%
loss). Sounds very inefficient to me.

Also, if you have a freezer full of frozen meat, for example, it
could be worth a thousand dollars or more at today's prices. Your
generator or main engines could break down and you just lost your
meat. An adequate supply of propane will forestall that eventuality.

I believe that the "propane fridge" that you are talking about is the
same sort of thing as the old "kerosene fridges" that use heat to
work. If so isn't there a pilot light down in the bottom that is on
all the time.

If that is what you are referring to I saw one in a 50 ft boat in
Malaysia once. The guy that owned the boat was changing out an old one
and replacing it with another. It seems to me that he said that the
fridge needed to be gimbaled to keep it as vertical as possible other
wise the flame wasn't directed to the correct place.

A lot of guys standing on the dock and making comments but he said
that he'd had the old one for a number of years with no difficulties,
other worrying about whether he had enough LPG to last till he got to
a place to buy more.

I have also heard that for monohull sailboats that operate
on an angle much of the time they are sailing, a propane
fridge/freezer needs to be gimbaled.

But for what Wayne has - a big motorboat - a propane freezer
in the cockpit would not need to be gimbaled. The only real
disadvantage of propane is it can blow up if there's a leak.

But, with a good installation and some electronic safety
gadgets it's not really anything to worry about. I used to
hate the very thought of propane until about three winters
ago it got cold-very cold. So, I made myself a nice propane
heater for a cost of less than thirty bucks and got a tank
of Blue Rhino propane for it. I used about half of a 20lb
tank in a week keeping the boat cozy warm running it on
the lowest setting (while I was aboard).

Since then I haven't had to use it at all but still have
about half a tank of propane left. The tank resides about
ten inches from my face under the front of the v-berth. If
it were to leak I would smell it immediately.

I'm not concerned at all about fires or explosions.

I'm impressed by the Dometic brand propane refrigerators/freezers
installed in some of the larger RV's. A friend of mind told
me his RV fridge runs about a month on a 20 pound tank. I opened
it and it was cold - just like a home stand-up fridge. I
couldn't even hear it running. The Dometic can use propane, 12 volts
or 120 volts.

And years ago I watched (from a distance) a LPG terminal stocked with
tanks for delivery to homes burn and I also watched them haul the
burning fifty foot sailboat out of the marina with a dinghy to prevent
other boats catching fire and "Boat Lagoon", the first marina in
Phuket, originally used a repainted burned out hulk, the results of a
LPG fire. as a sign post at the entrance gate.

All very spectacular. Spectacular enough that I mounted my LPG bottles
outside the enclosed part of the boat and used a shutoff valve at the
bottle.

It is sort of like thru-hulls. they probably won't fail but if they do
one is in a lot of water (hot or otherwise).
--
Cheers,

Bruce in Bangkok