A key part of passive fire protection is suitable heat and smoke extraction. Mechanical heat and smoke extraction systems often use ventilation ducts running through more fire compartments. It is important to note that regular steel plate ventilation ducts in themselves fail to meet fire protection criteria, as they quickly heat up and deform in fire. Steel ventilation ducts for heat and smoke extraction should be certified, provided with special heat insulation and occasionally with heat dilatation compensators, often reinforced inside.
Besides the above-mentioned very complex steel ventilation duct system, ventilation ducts built from calcium silicate fire protective construction boards are optimised and tested specifically for heat and smoke extraction. Such modern, certified systems are offered by Promat, a manufacturer of fire protection products, and their heat and smoke extraction system, certified as EI 120 S multi, was applied in Puskás Ferenc Stadium. The system is certified for up to 120 minutes by the standard test using a closed-space fire curve, is built from calcium silicate construction boards of fire protection class A1 and can be assembled on the spot as three- or four-sided structures. While conventional ventilation ducts are built and heat-insulated in two steps, this system can be built in a single step, optimising both construction time and material procurement.