The structural stability of intake and exhaust air towers is tested by structural analysis calculations. Depending on on-site conditions, the towers can be attached to the walls of the building with brackets for extra support. For freestanding intake and exhaust air towers anchor cages are usually used. The anchor cages, designed to be set in concrete, can be delivered prefabricated or, as in the photo here, as a double-flange construct with gusset plates, which are bolted to the existing substructure – Design and drawings “made by LBF Technik”!