Gogarty wrote in
:

My understanding of flame driven refrigerators (they used to be common
in homes -- Nash Kelvinator, was it?) is that the unit or at least the
working guts must be absolutely level at all times, which makes them
impractical for use on boats.



Absorption fridges are used in virtually all motorhomes and travel trailers
and make ice just fine from propane riding down the interstate. The
refridgerant is ammonia and water. When water and ammonia mix, heat is
absorbed. The burner boils off the water into steam which is condensed
then recycled to the cooling coils to repeat the process.

These absorption fridges are never "level" on the road, they are tossed
back and forth like your boat. BUT, when they are PARKED, dead still, they
must be leveled to provide the proper liquid levels in them to prevent
vapor lock. As you boat tilts back and forth, pitching and rolling even at
the dock, the absorption fridge (Dometic is a great brand) will work just
fine. Kerosene power, or diesel if you like, has the problem of CO being
generated that must be carefully vented away from sleeping compartments.
In the "campers", the problem is easily solved because the whole unit is
left out in the weather with louvered doors and a big flue out the top of
the camper. Venting the heat and fumes generated in the boat becomes the
same problem as any open flame heating system does.

I had two trailers and a motorhome and all of them had absorption fridges
that were 3-way...115VAC, 12VDC and propane. The electric side is just a
calrod element in the boiler around the propane burner. Anything that will
heat that boiler will work, even wood and I believe Scandanavia has many
wood-powered models...or used to.

--
Larry