Abstract: An air passage controlling system for selecting an air outlet mode of an air conditioning apparatus includes a driving shaft, an intermediate shaft, a driven shaft and a film door disposed between the shafts. The film door has a door opening through which air flows, and is disposed inside an air duct to be opposite to a duct opening of the air duct. The duct opening is opened and closed by moving the film door to select an air outlet mode. The driving shaft and the driven shaft are respectively connected to a driving pulley and a driven pulley which are linked via a wire. The driving shaft is rotated by a DC motor, and a rotation angle of the driving shaft is detected by a multi-rotation type potentiometer. The DC motor is controlled by an ECU according to the detected rotation angle of the driving shaft so that the film door is moved to a set position.

Abstract: An automobile air conditioning system including a fan unit for generating an air flow. The air flow is directed to the passenger compartment of the automobile through a first air duct which is provided downstream of the fan unit. A second air duct branches from the first air duct which extends over and in parallel to the first air duct. A filter is provided between the first and second air ducts for cleaning the air flow to the second air duct from the first air duct through the filter. Further, the air conditioning system is provided with means for selectively directing the air flow from the fan unit to the passenger compartment through the first air duct or through the first and second air ducts.