Ventilation ducts provide possible routes for smoke spread between adjacent rooms or compartment in case of a fire. Fire spread from one fire compartment to another (e.g. between floors) must be avoided to keep the building safe and to give tenants the necessary time to escape and to the fire brigade the time to control the fire. Specifically in ventilation systems, the smoke and fire spread can be prevented installing dampers or smoke/fire barriers and shut down the ventilation system in the event of fire. This is not always the best cost-effective solution. Moreover, it must be considered that typical steel sheet ducts can be deformed rapidly from the effects of fire, creating potential collapse of the vertical compartment element, especially if are light partition, and/or leaving a space around the penetration onto the walls and ceilings where fire and smoke can easily pass.