Introduction to Vapor Absorption Refrigeration System (VARS)

The compressor in vapor absorption system consumes a lot of energy. To avoid this, vapor absorption refrigeration system has been developed. The absorption system uses heat energy supplied by a flame or some other source of heat.

Michel Faraday experiment on liquefaction of gas:

vapor absorption refrigeration system is based on the principle of experiment developed by Michel Faraday. He sealed in a bent test tube a compound of silver chloride (a white powder) and dry ammonia gas which have been absorbed by the powder. He heated the end of tube containing the powder and at the same time, cooled the opposite end of the tube with water. Ammonia vapor was released during the application of heat and was condensed to cool end of the tube. When the flame under the powder was extinguished, vapor that had not been liquefied was reabsorbed by the powder reducing the pressure on liquid ammonia. The liquid ammonia begins to boil, change back to vapor and was reabsorbed by the powder. The end of tube containing boiling liquid was intensely cold. The evaporating ammonia having drawn heat from the nearest substance, the test tube itself. Read more