Electric heating device, particularly for a heating or air-conditioning unit in a vehicle

A heat transfer device, especially for a motor vehicle, comprises a component (6,6',6) with a source of electric current whose temperature changes depend on the flow through it and a second component (7) electrically or thermally connected to the first. One component can move to change the flow direction of a medium around the unit. An independent claim is also included for an air flow channel, especially for a motor vehicle, for the above.