Mazda 2011 CX-9 Owner's Manual page 265

Interior Comfort
Climate Control System
Vent Operation (Rear)
qAdjusting the Vents
Directing airflow
You can direct air flow by moving the adjustment knob.
NOTE
When using the air conditioner, mist may come out from the vents. This is not a sign of trouble but a
result of humid air being suddenly cooled.
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