IJR highlights: impacts of refrigerant charge on system performance

A team from Purdue University recently published* in the International Journal of Refrigeration a study showing the impact of charge level on capacity and efficiency for several heat-pump and air-conditioning units tested at various refrigerant charge levels.
A team from Purdue University recently published* in the International Journal of Refrigeration a study showing the impact of charge level on capacity and efficiency for several heat-pump and air-conditioning units tested in the laboratory at various refrigerant charge levels.

For all the systems considered, a refrigerant charge reduction of 25% led to an average energy efficiency reduction of about 15% and cooling capacity degradation of about 20%. Furthermore, the authors found that an undercharge of about 25% would cause an average penalty in terms of Seasonal Energy Efficiency Ratio (SEER) of about 16% and cost an average annual USD 100 per ton of rated capacity for typical electricity rates.
Previous research estimates on residential air conditioners claimed that on average, 55% of systems were undercharged by 10-30% due to incorrect measurement of charge level during installation or service.

* W. Kim, J. E. Braun, Evaluation of the impacts of refrigerant charge on air conditioner and heat pump performance”, IJR, vol. 35-7, November 2012

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