Perfect for SHTF times. Off the grid; uses no electricity. Operates on natural gas or propane. No moving parts. Single door with freezer section across the top. Currently set up for natural gas. This 75 year old wonder is in excellent shape and has been in use in my home for the past four years. Must be picked up in north central West Virginia; and will take three strong men to move it. Asking what I paid for it. $650.
@johnbb They're pretty common in RVs, although they're not limited to those. I have a nice one in my Travel Trailer. I don't think there's a whole lot that can go wrong with them, unless the tubing is punctured and all the gas leaks out. Your best bet is to look at "How Stuff Works" or one of the other web sites. Some have diagrams as well as explanations. Gas and Propane Refrigerators If you own an RV, chances are you have a gas- or propane-powered refrigerator. These refrigerators are interesting because they have no moving parts and use gas or propane as their primary energy source. Also, they use heat to produce the cold inside the refrigerator. A gas refrigerator uses ammonia as the coolant, and water, ammonia and hydrogen gas to create a continuous cycle for the ammonia. The refrigerator has five main parts: Generator - creates ammonia gas Separator - separates the ammonia gas from water Condenser - where hot ammonia gas is cooled and condensed to create liquid ammonia Evaporator - where liquid ammonia converts to a gas to create cold temperatures inside the refrigerator Absorber - absorbs the ammonia gas in water It works like this: Heat is applied to the ammonia and water solution in the generator. (The heat comes from burning gas, propane or kerosene.) As the mixture reaches the boiling point of ammonia, it flows into the separator. Ammonia gas flows upward into the condenser, dissipates heat and converts back to a liquid. The liquid ammonia makes its way to the evaporator where it mixes with hydrogen gas and evaporates, producing cold temperatures inside the refrigerator's cold box. The ammonia and hydrogen gases flow to the absorber where the water collected in the separator in step No. 2 mixes with the ammonia and hydrogen gases. The ammonia forms a solution with the water and releases the hydrogen gas, which flows back to the evaporator. The ammonia-and-water solution flows toward the generator to repeat the cycle.
It seems to me that solar technology either heating or electric could be adapted to run these ammonia cycle refrigerators. Or a hybrid gas/solar.
Any heat source can be used to run an Ammonia over Hydrogen refer system… At our place in the Alaskan Bush, ours is an RV Type Three-Way… The heat comes from one of three sources… A 12Vdc Heating Coil. A 120Vac Heating Coil. Or a Propane Burner. The Control System runs on 12Vdc, and it can switch between the sources, automatically, depending on what is available… We set ours up for 120Vac, if it is available, first, then Propane, second, and 12 Vdc as a last resort… Works very well…
have an old Holiday Rambler travel trailer (1967) with a propane fridge that's 3-way also, getting rid of trailer soon but will save fridge, it's small but works.