Abstract: Device for the air-conditioning and/or monitoring of building or warehouse areas, containing a housing consisting of plastic or composite material shaped as a hollow body and having air entry, air guidance and air exit sections, at least one fan roller provided with a plurality of profiled fins made of composite material or plastic, and drivable by at least one electric motor, the fan roller being positionable inside the housing, and a casing for the housing, formed by a flexible plastic or composite material panel that can be connected to the housing, wherein an end section of the casing can be releasably connected to a housing section, an approximately arc-shaped contour of the casing is formed by bending the casing lying outside the housing, and after further bending of the casing, the free end thereof can be releasably fastened to a different housing section.