Hi DanoT,
Gas Refrigerator: The refrigerant in a propane/electric refrigerator is a mixture of distilled water, ammonia, sodium carbonate and hydrogen gas, all at 200 psi pressure.
Storage is not a problem--but running one in cold may be an expensive lesson.
Absorption fridges are a pain. In the summer we need about 6 hours to cool them off, and in winter they really ought to be "warmed up" before they are turned on.
If I get some cold weather I'll do some "back yard" experiments to see how long it takes to get up to a safe operating temperature.