1999 Buick Regal Owner's Manual - Page 142

yellowblue Heating On cold days, use HTR with the temperature knob and lever all the way in the red area. The system will bring in outside air, heat it and send it to the floor ducts. If your vehicle has an engine coolant heater, you can use it to help your system provide warm air faster when it's cold outside -- 0_F (-18_C) or lower. An engine coolant heater warms the coolant your engine and heating system use to provide heat. See "Engine Coolant Heater" in the Index. Ventilation For mild outside temperatures when little heating or cooling is needed, use VENT to direct outside air through your vehicle. Your vehicle also has the flow-through ventilation system described later in this section. With this system, you set a temperature. You can then either let the system automatically control airflow direction and force to maintain the temperature, or you can manually adjust it. The system works best if you keep your windows closed while using it. Automatic Control For the most efficient operation, you should set the system temperature and press AUTO. The system will select the best fan speed and airflow settings to keep you comfortable. The air conditioning compressor will run if the outside temperature is above 40_F (4_C). You may notice a delay of two to three minutes before the fan comes on at start up in cool weather. Dual Automatic ComforTemp Climate Control (If Equipped) Defogging and Defrosting Your system has two settings for clearing the front and side windows. To defrost the windows quickly, use FRONT with the temperature knob all the way in the red area. For maximum defroster performance, set both driver and passenger temperature controls to the warmest setting. To warm passengers while keeping the windows clear, use BLEND. 3-4