There are three distinct parts in the smoke extraction for underfloor parking facilities: the extract system inside the garage, the engine exhaust duct of the extraction and the pipe which is leading the gas out of the garage. Each element has its classification of fire resistance.

Jeremias offers the third element, the ventilation chimney system, which goes out of the garage. This duct needs a fire resistance classification of at least EI60 to prevent that the pipe could spread the fire further in the building. Besides the fire resistance must be indoor fire as local ventilation is the local risk.