Heat exchanger and method of operation

A heat exchanger of an electrically driven motor vehicle, the heat exchanger comprising:

• a tube-rib block having at least two tubes and at least two ribs, the tubes being arranged essentially in parallel to each other and spaced a distance apart, and the ribs each being arranged between two adjacent tubes, the ribs touching the two adjacent tubes;
• at least one manifold arranged on one of the sides of the tube/rib block for the supplying of fluid to the tubes of the tube/rib block and for removing the fluid from the tubes of the tube/rib block;
• and
• a cover device arranged downstream and/or upstream from the tube/rib block for controlling air flow through the tube/rib block temporarily or in certain regions of the tube/rib block for a defined removal of water from the tube/rib block,
• wherein a first air channel and a second air channel are provided downstream from the tube/rib block, an air flow control element being provided, by which the second air channel is connected to the first air channel so that air may be conducted out of the second air channel into the first air channel or by which the second air channel is disconnected from the first air channel so that the air from the second air channel is able to flow out independently of the first air channel.