1999 Chevrolet Tahoe Owner's Manual - Page 159

yellowblue Air Conditioning On hot days, open the windows long enough to let hot air inside escape. This reduces the time it takes for your vehicle to cool down. Then keep your windows closed for the air conditioner to work its best. The recirculation button, between the fan and temperature knobs, allows the air inside your vehicle to be recirculated. This setting helps to maximize your air conditioner's performance and your vehicle's fuel economy. This setting also cools the air the fastest and can be used to keep unwanted odors and/or dust from entering the vehicle. When using the air conditioner, turn off recirculation after the vehicle reaches a comfortable interior temperature. When the right knob on the control panel is between HEATER and DEFROST, the recirculation feature will not function. The A/C button, between the temperature and mode knobs, allows the air coming into your vehicle to be cooled. This setting is useful for normal cooling on hot days. When you use A/C with the recirculation button pushed in, turn off recirculation as soon as the vehicle reaches a comfortable interior temperature. With the A/C on, move the temperature knob to MAX for maximum cooling. This setting also puts the system in the recirculation mode and helps to maximize your air conditioner's performance and your vehicle's fuel economy. This setting also cools the air the fastest. After the vehicle's interior reaches a comfortable temperature, move the temperature knob clockwise to place the air conditioning system in the normal mode. Heating The heater works best if you keep your windows closed while using it. On cold days, use the HEATER or VENT/HEAT setting with the temperature knob in the red area. If you use the engine coolant heater before starting your engine in cold weather, 20_F (-8_C) or lower, your heating system will produce warmer air faster, to heat the passenger compartment in cold weather. The use of an engine coolant heater also reduces the time it takes for the engine to reach normal operating temperature, and shortens the time it takes the heater to reach full output. For more information, see "Engine Coolant Heater" in the Index. 3-7