EVOLUTION OF A PROPER ALTERNATIVE REFRIGERANT FOR R-22 IN AIR CONDITIONING SYSTEMS

The present research is concerned with the future phase-out of halocarbon types of refrigerants used in the vapour compression refrigeration systems. A window-type air conditioner is selected for the tests to be conducted with three different types of 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 other types which are considered to be as environmental friendly refrigerants for smooth operation. The refrigerants selected for this object were the zeotrop blends R-407C and R-407A for their favourable thermal properties and acceptable pressure and temperature ranges. The effect of replacing these refrigerants as drop in alternatives on the performance of the cooling unit was studied. The performance characteristics comprise of cooling capacity ( ), power consumed by the compressor ( ) and the coefficient of performance (COP) of the air conditioning unit were obtained. The results showed that the drop in technique of R-22 by R-407C and R-407A improved cooling capacity up to (12%) and (25%) respectively. R-407C exhibited lower power consumption than that experienced with R-22 tests by (4%). On the contrary, R-407A showed a higher consumed power than that of R-22 by (4%). R-407C and R-407A showed a significant increase in (COP) by (21%) and (27%) respectively for the operating conditions presented here.