Experimental Perspective Assessments for a Proper Refrigerant Alternative to R-22 in a Window-Type Air Conditioning Unit

Abstract

The present research is concerned with the future phase-out of halocarbon types of refrigerants used in the vapor compression refrigeration systems. A window-type air conditioner is selected for the tests to be conducted with two different refrigerants. It is well known that these cooling units are wide spread in their applications and are circulating R-22 as a refrigerant. It is intended to replace this type of refrigerant by another type which is considered to be as environmental friendly refrigerant for smooth operation. The refrigerant selected for this object was R-407C for its favorable thermal properties and acceptable pressure and temperature ranges. The effect of replacing this refrigerant as a substitute on the performance of the cooling unit was studied. The performance characteristics comprise of cooling capacity (Q evap ), power consumed by the compressor (W ̇_cons ) and the coefficient of performance (COP) of the air conditioning unit were obtained. The results showed that the pressure ratio of the R-407C for a proper operation was higher than that of the R-22 by a mean value of (13) %. The power consumed per ton of refrigeration by the unit when circulating R-407C was about (19) % greater than the R-22 values for the whole range of tests. Further, the experimental work has revealed that the actual COP of the unit was reduced by (17) % when circulating the alternative R-407C for the test conditions. The results also showed that this alternative for the present refrigerant with existing cooling unit requires the attention to the mass flow rate of refrigerant circulated and the pressure and temperature ranges throughout the system.