The concept of fire ventilation is understood here as a system of smoke exhaust and exhaust ventilation that ensures the removal of smoke and hot gases generated during a fire and the air supply system to the zone, in which there is smoke, ensuring smoke buoyancy towards the exhaust points and a constant inflow of external air. Fire ventilation provides protection against smoke in staircases, fire vestibules and crane shafts for rescue teams and escape corridors.
In terms of fire ventilation requirements, the new regulations introduce significant changes and define its technical parameters to a large extent. The installation of smoke exhaust ventilation should ensure smoke removal with an intensity of at least 10 changes per hour, I guess, that a different number of replacements was calculated to prevent smoke in the protected rooms and escape routes. Criterion 10 changes per hour should be applied to large rooms or buildings, while designing a fire ventilation system in a multi-storey building, with separate escape routes, detailed calculations of the amount of ventilation air must be performed, based on the available rules of technical knowledge.

The installation of smoke exhaust ventilation should be provided with a constant inflow of external air, supplementing the air shortages resulting from its discharge along with the smoke. This inflow should be realized by means of an air supply installation, in a way that forces the smoke to be forced out of the zone where people stay. The requirements for fire resistance of the air supply system are determined on the basis of the requirements for ventilation and air conditioning systems, taking into account the principles of technical knowledge relating to the specific operating conditions of the air supply system and its function..

Smoke exhaust ventilation ducts should have at least fire resistance class (He) the ceiling, resulting from the fire resistance class of the building,. Since, in accordance with the Technical Conditions, fire dampers in the smoke exhaust ventilation ducts should meet the criteria of fire tightness and insulation (He), and in the case of connecting these pipes with the ventilation and air conditioning system – also smoke-tight, this requirement also covers fire ventilation cut-off dampers. You should pay attention here, that the combination of smoke exhaust ventilation with comfort ventilation and air conditioning in high-rise and high-rise buildings is a solution not recommended due to the diversity of the basic functions of these installations. Due to the specific requirements related to the location of supply and exhaust points and the required flow rate for fire ventilation, it is practically impossible to use a comfort ventilation or air conditioning system for this purpose. It is much more difficult to provide a systematic inspection and guarantee of reliability for a complex and constantly functioning ventilation system, which, in the event of a fire, would change its function to a fire installation. Only independent fire ventilation, repeatable on each floor, enables its systematic and simple control and guarantees reliable operation of all devices in the event of a fire.

The upper edge of the air supply grilles belonging to the fire ventilation system should be at a height of not more than 0.8 m above floor level, and the lower edge of the exhaust grilles – at a height of not less than 1.8 m above floor level. The exhaust grilles should be arranged in a way ensuring even smoke removal from the room, the distance between them should not be greater than 10 m. Such a location of the supply and exhaust grilles, while ensuring appropriate air flow velocities in them, does not interfere with the natural stratification of smoke on escape routes and ensures that they are kept free from smoke up to a height of at least 1.8 m above floor level. The smoke exhaust ventilation fans should be resistant to the temperature of 400 ° C for at least 120 min or exposed to such a temperature, which is based on the expected temperature and time for the removal of fire gases.