A thermoelectric heat exchanger assembly (100, 200) configured to heat a first portion (112, 212) of a fluid flowing through said assembly (100, 200) and cool a second portion (114, 214) of the fluid flowing through said assembly (100, 200), wherein the first portion (112, 212) is segregated from the second portion (114, 214), said assembly (100, 200) comprising: a first thermoelectric device (116, 216) configured to heat said first portion (112, 212) of the fluid; and a second thermoelectric device (118, 218) configured to cool said second portion (114, 214) of the fluid; characterized in that said assembly further comprises tubes (248, 250) configured to transfer thermal energy between the first thermoelectric device (116, 216)) and the second thermoelectric device (118, 218) via evaporation and condensation of a working fluid contained within the tubes (248, 250); and that said tubes (248, 250) comprise: a first tube in thermal communication with the first thermoelectric device and configured to contain a working fluid; a second tube in thermal communication with the second thermoelectric device and configured to contain the working fluid; wherein the assembly further comprises: a first shell defining a first cavity oriented to contain the working fluid in a substantially liquid phase; a second shell defining a second cavity oriented to contain the working fluid in a substantially vapor phase, wherein the first tube and the second tube are sealably coupled to the first shell and the second shell, and wherein the first cavity and the second cavity are in fluidic communication through the first tube and the second tube. a first thermoelectric device (116, 216) configured to heat said first portion (112, 212) of the fluid; and a second thermoelectric device (118, 218) configured to cool said second portion (114, 214) of the fluid; characterized in that said assembly further comprises tubes (248, 250) configured to transfer thermal energy between the first thermoelectric device (116, 216)) and the second thermoelectric device (118, 218) via evaporation and condensation of a working fluid contained within the tubes (248, 250); and that said tubes (248, 250) comprise: a first tube in thermal communication with the first thermoelectric device and configured to contain a working fluid; a second tube in thermal communication with the second thermoelectric device and configured to contain the working fluid; a first tube in thermal communication with the first thermoelectric device and configured to contain a working fluid; a second tube in thermal communication with the second thermoelectric device and configured to contain the working fluid; wherein the assembly further comprises: a first shell defining a first cavity oriented to contain the working fluid in a substantially liquid phase; a second shell defining a second cavity oriented to contain the working fluid in a substantially vapor phase, wherein the first tube and the second tube are sealably coupled to the first shell and the second shell, and wherein the first cavity and the second cavity are in fluidic communication through the first tube and the second tube. a first shell defining a first cavity oriented to contain the working fluid in a substantially liquid phase; a second shell defining a second cavity oriented to contain the working fluid in a substantially vapor phase, wherein the first tube and the second tube are sealably coupled to the first shell and the second shell, and wherein the first cavity and the second cavity are in fluidic communication through the first tube and the second tube.