A heat transfer system includes a working fluid and an electrochemical compressor. The working fluid is made up of a polar solvent that primarily acts as a condensable refrigerant and hydrogen that primarily acts as an electrochemically-active component. The electrochemical compressor includes an inlet fluidly coupled to an evaporator to receive the working fluid; an outlet fluidly coupled to a condenser; and one or more electrochemical cells electrically connected to each other through a power supply. Each electrochemical cell includes a gas pervious anode, a gas pervious cathode, and an electrolytic membrane disposed between and in intimate electrical contact with the cathode and the anode to pass the working fluid.