ROMFILTERENHET FOR BESKYTTELSESROM

The shelter filter for air-raid shelters is intended to purify air, in the ventilation installation, in particular air which has possibly been ABC-contaminated. For this purpose, the filter has a particulate filter and a downstream gas filter. In order to supply air-raid shelters with normal air and simultaneously protect the filter material, the said air is channelled in a bypass line past the shelter filter or through an intermediate piece which has been inserted in place of the shelter filter when the latter has been removed. Changeover to ABC-protection requires changeover via valves or else exchange of the intermediate piece for a shelter filter. The shelter filter according to the invention contains the ABC-part and the bypass part in a housing and separated from each other by a partition. Each part has the same connecting pieces for the supply and discharge of air. In order to change over the ventilation option, after the connecting pieces have been detached, the housing only has to be rotated through 180 DEG and then attached again. Only the shelter filter is required which, incorporated in the ventilation installation, is held ready and available.