Being 9 or 10 years old at the time I was fascinated that a device
> could be built that could make cold using only a flame.
I distinctly remember gas refrigerators, and yes, I was also fascinated by the fact they used heat to produce cold. When I was about that age, some neighbors of ours in an upstairs apartment had one, a Servel. It was connected by a stubbed-out pipe from the connection to the gas range. It did have a power cord -- for the light. ;-)
I don't recall if it was vented or not. (Anybody know?)
Later I learned that these used a hydrogen and ammonia refregeration unit.
Back in the 1970's a friend of mine had a 50's vintage suburban ranch house which had a gas central air unit. At the time it worked, but it was incredibly expensive to operate due to escalating gas prices. I remember the tag on the inside unit had a picture of a blue flame and the expression:
'Ice Blue Gas Flame.'
I also vaguely recall gas deep freezers as well.