Air conditioner system with defrost door modulation as a function of ambient temperature

摘要

The operation mode of an air conditioner system is automatically controlled between VENT mode, BI-LEVEL mode, HEAT mode and so forth according to environmental conditions. The air conditioner system includes a control unit for operation mode selection. In HEAT mode, the control unit adjusts ratio of the conditioning air discharged from a defroster nozzle to that from a foot nozzle according to environmental conditions or on the basis of a required discharge air temperature necessary to obtain a desired air temperature in the vehicular cabin. The air conditioner system also includes a sensor for monitoring a preselected air conditioner control parameter for producing a sensor signal. The control unit calculates the required discharge air temperature on the basis of the monitored parameter.