Cadillac 2011 STS Owner's Manual page 234

Use the lever located in the center of each outlet to
change the direction of the airflow, either side-to-side or
up and down. Use the thumbwheels to open or close
the outlets to adjust the airflow.
Turn the thumbwheel towards the vehicle door to open
the outlets and allow the maximum amount of air to
enter your vehicle. Turn the thumbwheel towards the
center console to close the outlets and minimize the
amount of air entering the vehicle.
4-48
Clear away any ice, snow or leaves from the air
inlets at the base of the windshield that may block
the flow of air into your vehicle.
Use of non-GM approved hood deflectors may
adversely affect the performance of the system.
Keep the path under the front seats clear of
objects to help circulate the air inside of your
vehicle more effectively.
If the airflow seems low when the fan speed is at
the highest setting, the passenger compartment
air filter may need to be replaced. For more
information, see Passenger Compartment Air
Filter on page 4 50.