Air conditioning system for automotive vehicles

摘要

An automotive air conditioning system designed to switch a ventilation mode to an air recirculation mode automatically when the contamination of outside air is greater than a given level. The system includes a mode selection prohibiting circuit that prohibits the switching between the air recirculation mode and the ventilation mode and operates the air conditioning system in the ventilation mode when the vehicle is traveling at high speeds or when the outside temperature is relatively low. This allows fresh air having a relatively lower humidity to be drawn into the passenger compartment, thereby avoiding fogging of inner surfaces of windows of the vehicle.