Air drying installation for motor vehicles

Abstract

Apparatus for reducing the air moisture in a passenger compartment of a motor vehicle. The apparatus has a housing which is connected to a supply air duct and a discharge air duct of the passenger compartment. In the housing, there is arranged a secondary air chamber and a main air chamber, following in the direction of flow to the passenger compartment. Arranged between the secondary air chamber and the main air chamber is an air-permeated wall element of hygroscopic material for dehumidifying the air. To ensure dehumidification, there is arranged a second secondary air chamber, which is separated from the main air chamber by a second air-permeated wall element of hygroscopic material. For controlling the air volume, in each air chamber there is arranged an air flow control element, such that, in a first position of the air flow control elements, an air flow entering the one secondary air chamber is ducted through the first wall element and, as a dried air flow, is fed via the main air chamber to the supply air duct of the passenger compartment and that an air flow ducted into the main air chamber as a desorption flow is directed through the second wall element and discharged through the other secondary air chamber. In a second position of the air flow control elements, the air ducting is changed correspondingly.