Shaft smoke extraction
An elevator shaft smoke extraction is a safety device in the event of fire, which is used depending on the nature of the elevator shaft or the height and use of a property in elevators . It ensures the escape of fire gases and smoke from the elevator shaft. The country-specific building and construction regulations can be found in the country-specific building and construction regulations, when smoke extraction openings and in what size must be present in the shaft cladding. B. LBO and DVO_BauO. However, it must be ensured that in addition to elevator shaft smoke extraction, which must meet the requirements of building law, elevator shafts must also meet the requirements of elevator shaft ventilation, which result from the implementation of the elevator directive 95/16 / EC.
Legal situation from the point of view of building law
In Germany's state building law, smoke extraction openings are typically prescribed, with the lift shaft having to be extracted directly into the open air or via the elevator levels, depending on the height and use of a property.
Legal situation from the perspective of elevator law
The EC directive on the harmonization of legislation on lifts 95/16 / EC defines basic safety and health requirements of general scope across Europe. Among other things, it is required here - "The color baskets are to be designed and built in such a way that sufficient ventilation is guaranteed for the occupants even when they are stopped for a long time". In order to make it easier for elevator installers to demonstrate compliance with these basic requirements, the European Standardization Committee (CEN) has drafted harmonized standards for protection against risks arising from the design and installation of elevators and for checking compliance with the basic requirements. In the harmonized standard EN 81-1 / 2 z. B. recommended that the size of the elevator shaft ventilation opening be 1% of the shaft cross-section. The new harmonized standard EN 81-20, on the other hand, does not specify the size of the ventilation opening, but refers to a detailed, informative annex, which, among other things, contains the essential risks when determining appropriate elevator shaft ventilation. Both standards require that the elevator system must be kept free from harmful gases. Accordingly, the discharge of smoke in an elevator shaft must not only be assessed within the framework of building law, but also within the framework of elevator law using an appropriate hazard analysis. In the case of passenger elevators with closed elevator shafts without a smoke extraction opening required by building regulations, the shaft ventilation must take place directly to the outside in accordance with elevator law. Insofar as the build-up of thermal in the elevator shaft via elevator shaft ventilation into the interior of the property has not been proven in individual cases by a scientific study, ventilation of the elevator shaft into the interior of the property is generally prohibited for safety reasons (see "Elevator shaft ventilation").
Uncontrolled duct smoke extraction
This is an exhaust air opening that leads from the shaft directly into the open. It is primarily used for smoke extraction in the event of a fire, but also to ensure an exchange of air in the lift shaft, provided that the lift shaft smoke is extracted via a common opening according to building regulations and ventilation according to lift law.
In the bay of existing smoke is due to the thermal transported from the smoke ventilation to the outside, rather than gush into other floors.
Controlled duct smoke extraction
More and more often, the smoke exhaust openings are temporarily closed with technical devices in order to avoid unnecessary loss of thermal energy. With the controlled smoke extraction from the shaft it is possible to comply with the building regulations - e.g. B. the state building regulations (LBO) and the Energy Saving Ordinance (EnEV) - to bring in line and at the same time to increase the security in the building. Such systems ensure that the smoke outlet opening opens immediately in the event of smoke development. In addition, the elevator control can be informed of the presence of smoke in the shaft via a potential-free contact. A subsequent evacuation trip of the car can only be carried out via the elevator control.
A controlled smoke control is used to allow the escape of warm room air through the flue gas opening of an elevator shaft to prevent. The smoke extraction opening is realized in such a way that it is only opened in certain situations and otherwise remains closed. A typical locking device is e.g. B. is an electrically operated louvre. This louvre is z. B. positioned from the inside of the shaft in front of or in the opening and controlled via a smoke detector. If smoke is detected, the flap opens and the smoke is extracted.
Controlled smoke extraction from shafts has almost become the standard for the construction of new residential and commercial buildings, but it is not a legal requirement. Since the amortization times for the investment costs are often relatively short, the heating and air conditioning energy costs can be reduced considerably. It also increases user safety.
It is important that such a controlled duct smoke extraction also permanently records the air quality and temperature in the duct or in the cabin and that the locking device opens if the limit value is exceeded . In the event of an elevator malfunction involving people being trapped, the oxygen content of the air in elevator cars can quickly reach a critical level, especially in low-energy or energy-efficient properties. (Example data: human air consumption approx. 3 m³ / h, air volume 35 m³, number of people 13). Modern ventilation controls for elevators already contain routines that open and close the smoke extraction openings depending on whether the elevator is used or at a specified interval.
For the retrofitting of existing elevator systems there are such systems today, which make retrofitting easily possible even with very old elevator systems that are still equipped with relay controls.
