How Does a Propane Fridge Work?

Most people are accustomed to an electric refrigerator, but where electricity is not supplied or feasible a propane fridge works well. For example, propane can be used as the coolant for refrigerators in RVs, boats or rustic cabins.

Main Components

A propane refrigerator is a closed system. Besides the actual "box" of the refrigerator, the system consists of a series of components that process the chemical reaction. The main parts include a generator, separator, condenser, absorber, cooling coils and evaporator.

The cooling agents that travel through this system are ammonia, distilled water and hydrogen gas.

The Cooling Process

Ironically, burning propane can produce the cold temperatures for refrigeration. The propane burner heats a generator that combines ammonia with water. As this liquid boils, it flows through piping to an area where the molecular differences separate the two. The ammonia turns to steam more quickly and rises out of the water. The water then goes to the absorber where it can be used later.

The ammonia continues to the condenser where it loses heat and once more returns to a liquid state. The ammonia then goes to the evaporator where it's mixed with compressed hydrogen gas. The chemical reaction causes the ammonia to evaporate again but, this time, into a freezing vapor.

The generator's pressure pushes the vapor through cooling coils. It then returns to the absorber where it again combines as a liquid with the water. The hydrogen gas goes to the evaporator.

The ammonia and water flow into the generator together and the cycle repeats itself, providing continuous cooling.