A device for control of the air flow rates into the instrument panel air outlets of a vehicle heating or air conditioning unit is described that is provided with a casing, with damper doors for both instrument panel side air outlets in the casing parts and at least one damper door for the instrument panel central air outlet in the casing part, whereby the damper doors are pivotably supported on one common shaft. Exactly one closing position is assigned to the damper doors in the first casing part, whereas several closing positions are assigned to the damper door in the second casing part continuously over a pivoting range of the shaft, whereby the closing position of the damper doors is arranged in the pivoting range of the damper door. This device enables separation and independent control of the air flow rates.