Abstract: A heat exchanger including a first tube including a first flat plate and a first shaped plate connected to each other to form a first tube channel extending along a first tube extension axis, a second tube including a second flat plate and a second shaped plate connected to each other to form a second tube channel extending along a second tube extension axis, the first tube and the second tube being fixed to each other by an interconnector. The first tube channel forms a first primary arm and a second primary arm extending parallel to each other along the first tube extension axis. The first primary arm includes a first primary inner fin and the second primary arm includes a second primary inner fin.