"Percival P. Cassidy" wrote in message
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I'm assuming that they work on a similar principle to the kerosene
refrigerators I recall from a few decades back; a neighbor in a rural area
of UK with no electric supply had one. Some of those used ammonia as the
refrigerant, but maybe the propane ones now use Freon.

IIRC, the heat of the flame raises the pressure of the refrigerant just as
the compressor does in an electric refrigerator.

Perce

IIRC, the flame boils the ammonia, it condenses, and as it does, cools,
hence, cooling. I know the large ice producing companies around the turn of
the century were ammonia powered. NO moving parts.

Steve