A system for mixing and distributing air in an aircraft cabin, comprising: a first, internal air supply line, a second air supply line at least partially surrounding the internal air supply line, and a mixed air distribution system for mixing the air supplied from the air supply lines and for distributing the mixed air. The mixed air distribution system comprises a plurality of outlet lines for the outlet of mixed air into the aircraft cabin. The two air supply lines comprise outlets which, in each case, discharge into the mixed air distribution system. The two air supply lines are thermally coupled, and the main directions of extent of the air supply lines and of the mixed air distribution system are oriented substantially parallel or collinear to one another.