Investigation of low Global Warming Potential working fluids for a closed two-phase thermosyphon

► Study of low GWP working fluids for thermosyphons. ► Thermal conductivity tested for four different working fluids. ► Validity of prediction models for the experimental results reviewed. ► Water-5% ethylene glycol can outperform R134a with a suitable temperature drop. ► The prediction model was found to have mixed results dependent on working fluid.