A thermoelectric device adaptable for heating and for cooling a fluid such as air. The device includes at least one thermoelectric module and at least one rotating heat sink that transfer heat between the thermoelectric module(s) and the fluid. The heat sink(s) are mounted on a shaft and include a plurality of thermally conductive impeller blades. The thermoelectric module(s) rotate with the heat sink(s) about the shaft. Because the thermoelectric module(s) are in direct contact with the thermally conductive impeller, heat is transferred more efficiently into and out of the thermoelectric device. Because the impeller blades also act as heat sinks, fewer components are needed than with conventional devices.