Disclosed is a system for thermally conditioning and pumping a fluid having use as a ventilation system for vehicle seats and other applications. The system includes a thermoelectric heat exchanger having a thermoelectric element (46) configured to pump heat from one body to another body. A pair of heat exchanger elements (42, 44) comprising rotor units are coupled to the thermoelectric element (46) for both transferring heat to and from the thermoelectric element (46) and generating a fluid flow across the thermoelectric element (46). The conditioned fluid may be placed in thermal communication with a variety of objects, one of which is a vehicle seat to provide localized heating and cooling of a person sitting on the seat.