Multipart housing of a fan

A housing of a fan with external covering,

• the housing comprises a housing body to accommodate fan components, the housing body defining a wall with a top end and a bottom end, the housing body has a polygonal shape, and
• a radial exterior face of the housing body is surrounded from the top end to the bottom end by the external covering in a circumferential direction over its full surface, so that a radial exterior surface of the housing is formed by an exterior surface of the external covering, and the external covering is detachably attachable to the housing body and the external covering is formed from a plurality of segments that are subdivided in the circumferential direction;
• the housing body has webs running in the circumferential direction, forming with stiffening ribs of the external covering a channel running at least for a portion in the circumferential direction;
• at least one of the webs extend in the radial direction as far as an internal surface of the external covering and forms a radial bracing and/or a guide for the external covering in a mounted position;
• and
• at least one of the webs is radially shorter than at least one of the other webs, and said at least one radially shorter web interacts with at least one of said stiffening ribs formed on the external covering to form the channel running entirely in the circumferential direction.