A refrigerator that has not been cleaned with an ammonia-based cleaner, yet still gives off a clear ammonia smell, is probably in need of repair. Small, portable refrigerators and older domestic units frequently contain ammonia-based coolants; consequently, a sharp, ammonia odour is often indicative of a coolant leak.
Long before the development of modern coolants, ammonia, or NH3, was routinely used to keep refrigerators cool, allowing homeowners to store fresh foods for short periods. While ammonia refrigeration is not as common these days, it is still used in miniature refrigerators or for portable units found in campers and RVs. One of the main advantages to using ammonia as a coolant is the characteristic pungent aroma it emits, allowing owners to detect even the slightest leak almost instantaneously. A rapid response often reduces the cost and complication of the repairs necessary to keep the unit in working order.
Advantages and Disadvantages
In addition to being readily detectable by the human nose, ammonia is also relatively cheap to produce and fairly efficient. Refrigerators that use ammonia do not use the standard compression/expansion cycles favoured by most modern refrigerators; they function on temperature fluctuations, allowing them to operate on limited amounts of electricity. On the downside, ammonia tends to be corrosive and is combustible when mixed with oxygen; therefore, in most domestic refrigerators, ammonia has been replaced with less toxic, less flammable chlorofluorocarbons or hydrofluorocarbons, more commonly known as CFCs and HFCs.
Ammonia vapours are highly irritating to the skin, eyes and respiratory tract. To prevent an accumulation of fumes, once an ammonia leak has been detected, open all doors and windows to increase the ventilation in the room. Should irritation occur, leave the room immediately, and rinse the affected areas with copious amounts of cold water.
Should an ammonia smell linger once the unit has been repaired, the aroma can be easily removed by filling a few shallow dishes with fresh coffee grounds and leaving them in the unit for 24 hours. The grounds are covered with tiny pores that readily absorb the odours in the air around them.