Ammonia Refrigerator Operating Temperature Requirements

Operating Principles

• Most ammonia refrigerators in recreational vehicles are heated with an electric heating element or LP gas, which warms a mixture of water and ammonia. Once warm, the ammonia/water mixture rises to the water separator in the refrigerator. The water condenses in the water separator and runs down to the boiler, while the ammonia turns into a vapor and moves into the condenser, where the cool air turns the ammonia vapor into liquid ammonia. Gravity sends the liquid ammonia down to the evaporator, where the liquid ammonia comes into contact with hydrogen, causing the liquid ammonia to evaporate again. The ammonia and hydrogen vapor pulls in heat from the refrigerator interior, and the warm air flows over the condenser, turning into cold air. This cold air runs down the evaporator coils and into the refrigerator compartment, cooling the refrigerator.

High Temperature Requirements

• According to the International Institute of Ammonia Refrigeration, the highest room temperature advisable when an ammonia refrigerator is in use is 104 degrees Fahrenheit. Proper ventilation is required when the ammonia refrigerator is running but is not necessary if the refrigerator is not in use during warm temperatures. Turn off the refrigerator if the interior temperature of the RV is above 104 degrees Fahrenheit, and be sure to adequately ventilate the area if you are using the refrigerator in temperatures below 104 degrees.

Low Temperature Requirements

• The lowest temperature at which an ammonia refrigerator will operate properly is minus 52 degrees Fahrenheit. At any point lower than minus 52 degrees Fahrenheit, a traditional CO2 or NH3 refrigerator will operate more efficiently.

Warning

• Ammonia can be very dangerous because of its highly corrosive nature, which could burn skin, lungs and eyes and can be fatal at even moderate levels of exposure. In addition, ammonia is flammable at concentrations above 15 percent -- or lower if mixed with lubricating oil. If you smell ammonia at any level, leave the area immediately and contact emergency services for assistance.