We present a comparison of the R-404A, R-448A and R-452A as drop-in replacements for R-218 refrigerant in high-tech electronics cooling.

The test were carried out in an oil-less experimental circuit originally designed for cooling of silicon chips with R-218. The circuit is equipped with tens of temperature, pressure and flow sensors and precise liquid and vapour pressure control. The same capillary was used for all the tested refrigerants providing mass flow of 1.2 g/s. Two-stage compression allowed to test suction pressures from 0.5-1 bar absolute.

The aim was to evaluate the possibility of replacing the rarely used, expensive and environment unfriendly R-218 by more ecological blends while achieving lower evaporation temperature and without hardware modifications to the existing circuit layout.

The results are applicable to low temperature systems with commercial two-stage reciprocating compressors that are being converted from R-404a to ecological alternatives R-448A/R-449A or R-452A.