Abstract: A refrigerant system uses a cofluid of ionic liquid and CO2 as a working fluid, and is adapted to selectively bind and release CO2 molecules from the ionic fluid in exothermic and endothermic processes, respectively. The refrigerant system includes a hermetic compressor which acts as a pump for the substantially uncompressible liquid working fluid. The compressor includes electrical components (such as the electric motor and various wires and connectors) which are electrically isolated from the working fluid in order to prevent electrical shorts caused by the conductive ionic fluid. At the same time, the ionic liquid may act as a lubricating fluid for the compressor components, eliminating any need for separate working and lubricating fluids.