2011 Chevrolet Avalanche Owner's Manual - Page 268

8-10 Climate Controls Operation Tips . Air Vents Use the air outlets located in the center and on the side of the instrument panel to adjust the direction and amount of airflow inside the vehicle. Move the louvers up or down to adjust the direction of the airflow. Use the thumbwheel next to or underneath the outlet to adjust the amount of airflow from the louvers. Keep the hood and front air inlets free of ice, snow, or any other obstruction, such as leaves. The heater and defroster will work far better, reducing the chance of fogging the inside of your windows. Keep the air path under the front seats clear of objects. This helps air to circulate throughout your vehicle. Adding outside equipment to the front of your vehicle, such as hood-air deflectors, etc., may affect the performance of the heating and air conditioning system. Check with your dealer before adding equipment to the outside of your vehicle. . .