NorthEGPhoto wrote:Sounds like it wouldn't be all that efficient either.. using electric heat to heat a thermocouple my guess?
Running a compressor probably uses much less power.
Most propane refrigerators are absorption units using an ammonia based refrigerant. That style of refrigeration was the most popular in the early days of refrigeration, and until pretty recently was still installed for huge rooftop units on commercial buildings. Now they are only popular for RV refrigerators and for unusual large industrial situations where free waste heat is available. If you are curios....
A refrigerant is a liquid that can change its boiling point. Drop the boiling point and boil it over here, send it over there, raise the boiling point and condense it over there, and go back around the loop again. Conventional units change the boiling point by changing the pressure, so they have an electric motor driven compressor to do that work. A vapor absorption refrigerant changes boiling point by changing the chemical concentration of a solution, and they use a burner to do that. At one point in the loop the burner boils the refrigerant, changing its concentration and boiling point. At another place the boiled-off part of the solution gets put back in making a closed loop cycle.
In my experience they are weak refrigerators that cool down slowly and poorly. But if you don't have electricity in an off-grid situation and don't want to bother with a generator (or listen to the noisy thing running) they might be the only option. Some of the remote fly-in fishing cabins we stayed at prefer the propane fridge just because they are silent.