Air conditioning apparatus for an automobile

摘要: A heater core 21 is connected to an engine cooling water line via inlet passageway 43 and a return 45. first valve 25a provided for controlling the amount of high temperature introduced 21, second 25b re-circulation low that has passed through core, 46. The supplied from 46 are controlled by on-off manner control valves 25b, respectively, thus ratio mixture water, which corresponds time average value into in accordance with duty signals operating 25 25b. This prevents depositing impurities at small gaps otherwise obtained between respective seats. Furthermore, under particular conditions, frequency cycle can be reduced, thereby prolong service life device. by-pass 47 preventing hammer.