Effect of Refrigerant Charge on the Performance of Air-Conditioning Systems

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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  • D.Y. Goswami
  • G. Ek
  • C.K. Jotshi
  • S.A. Sherif
  • F. Colacino


Original languageEnglish
Pages (from-to)1635-1640
Journal / PublicationProceedings of the Intersociety Energy Conversion Engineering Conference
Publication statusPublished - 1997
Externally publishedYes


Title32nd Intersociety Energy Conversion Engineering Conference (IECEC-97)
PlaceUnited States
Period27 July - 1 August 1997


An air-conditioning system operates in an optimal condition if the system is fully charged with specified amount of refrigerant. Poor field maintenance or refrigerant leakage causes low level of charge resulting in a lower thermal performance and higher operating cost. An experimental investigation was conducted to study the effect of low charge level of R-22 on the performance of a 3-ton residential air-conditioning system. The experimental results show that if a system is undercharged to 90%, the effect is small, 3.5% reduction in cooling capacity and 2% increase in COP. However, the system performance suffers serious degradation if the level of charge drops below 80%. An ice layer formed on the outer cooling coil surface impedes the heat transfer between the warm air and cold refrigerant vapor. An economic analysis shows that the cost of properly charging a system which has otherwise gone down to 85% charge level can pay for itself in savings in a short period of 3 to 4 months.