1998 Chevrolet Lumina Owner's Manual - Page 142

Air Conditioning On very hot days, open windows long enough to let the hot, insideair escape. This reduces the compressor A/C load, which should helpfuel economy. For quick cool-down on very hot days, use MAX with the temperature control all way in the blue area. If the this setting is used for long periods of time, the air in your vehicle may become dry. too For normal cooling on hot days, use A/C with the temperature control in the blue area. system will The bring in outside air and cool it. On cool but sunny days, the sun may warm your upper body, but your lower body may not be warm enough. You can use BI-LEVEL with the temperature control in the middle. The system will bringin outside air and directit to your upper body, while sending slightly warmed air your lower body. to You may notice this temperature difference more at some times than at others. If your vehicle has an engine coolant heater, you can use it to help your system provide warmfaster when it's air cold outside(0°F (-18°C) or lower). An engine coolant heater warms the coolant your engine and heating system uses to provide heat. "Engine Coolarg See Heater" in the Index. Ventilation System Adjust the direction of airflow by moving vents. the Your vehicle's flow-through ventilation system supplies outside airinto the vehicle whenit is moving. Outside air will also enter vehicle when the air conditioning the fan is running. Heating On cold days use FLOOR with the temperature control all the way in the red area. The system will bring in outside air, heatit and send it to the floor ducts.