Comparison of Vapor Absorption System with Vapor Compression System

Comparison of Vapor Absorption System with Vapor Compression System can be done in 9 aspects, they are energy input, moving part, evaporator pressure, load variation, evaporator exit, coefficient of performance, capacity, refrigerant and lowest temperatures.
Vapor Absorption System
Vapor Compression System
1 Energy Input Vapor absorption system takes in low grade energy such as waste heat from furnace, exhaust team or solar heat for its operations. Vapor compression system takes in high grade such as electrical or mechanical energy for its operation of compressor used in the cycle.
2 Moving part It uses a small pump as moving part, which is run by a small motor. It uses a compressor driven by an electric motor or engine.
3 Evaporator pressure It can operate with reduced evaporator pressure, with little decrease in refrigerant capacity. The refrigerant capacity decreases with lowered evaporator pressure.
4 Load variation The performance of vapor absorption system does not change with load variation The performance of vapor compressing system is very poor at partial load.
5 Evaporator exit In vapor absorption system, the liquid refrigerant leaving the evaporator does not put any bad effect on the system except to reduce the refrigerant effect. In a vapor compression system, it is desirable to superheat vapor before leaving the evaporator, so no liquid can enter the compressor.
6 Lowest temperature Since water is used as refrigerant, thus the lowest temperature attained is above 0°C. With cascading, the temperature can be lowered upto -150°C or even less temperature.
7 Coefficient of Performance The COP of the system is poor. The COP of the system is excellent.
8 Capacity It can built in capacities well above 1000 TR. For a single compression system, it is not possible to have a system with more than 1000 TR capacity.
9 Refrigerant Water or ammonia is used as refrigerant. Chloroflourocarbon, hydroflorocarbon and hydrochlorofluorocarbon are used in most of the systems.

Vinodh Reddy is an Editor-in-chief of ME Mechanical. He holds Bachelor of Engineering (Honours) degree in Mechanical Engineering from BITS-Pilani. He also writes for and EduGeneral.

All Comments

  • Hello, I would like to know that is there any company which is making vapor absorption system based refrigerator.

    aamir May 9, 2016 4:12 pm Reply
  • How would you compare VAS with VCRS for
    1. Cooling capacities
    2. Wear & tear and noise
    3. Effect of traces of liquid in the refrigerant at evaporator exit, and
    Applicability to remote areas.

    Avineel lal Aug 23, 2016 4:40 am Reply

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