Positive pressure ventilation
A positive pressure ventilation is a ventilation system, which in a certain part of the building a pressure generated. This can have the following reasons:
- Operation of clean room departments e.g. B. Chip manufacturing
- Operating rooms in the clinic
- Support of the fire brigade in case of fire
- NBC protection systems
- Commercial kitchens and other rooms for food processing should be protected from the ingress of germ-contaminated air, e.g. B. from rooms open to the public
The opposite of positive pressure ventilation is negative pressure ventilation . It is used when you want to prevent substances (especially gases) from leaving a room (e.g. chemical or bio laboratory).
Clean room
Overpressure ventilation is used in clean room departments in order to prevent contaminated air from entering production. The air conveyed into the room by the ventilation system is intensively cleaned beforehand. This also applies to operating theaters and intensive care units .
fire Department
An overpressure (smoke protection pressure system; RDA) is generated as system-technical fire protection for safety stairwells and for fire brigade lifts, so that the rescue and attack routes in buildings are protected against the entry of smoke. According to DIN EN 12 101-6: 2005 (smoke and heat exemption), buildings are divided into system classes. A differential pressure of 50 Pascal (Pa) +/- 10% is required, with an exchange of internal to external air between 0.75 m / s and 2.0 m / s depending on the system class. However, the differential pressure must not be exceeded, otherwise the escape doors can no longer be opened.
In Germany there is no uniform definition of structural fire protection . The report of the fire protection expert and the rules of the local fire brigade are decisive for fire protection in the building . In the case of overpressure systems in Germany, there is also talk of a pressure differential system, smoke displacement systems, safety ventilation systems.
The Austrian Technical Guideline for Preventive Fire Protection ( TRVB ) S 112: 2004 contains the definition of pressure ventilation systems (DBA). In Switzerland, new buildings are specified in the fire protection concept according to the strict rules of the European standard 12101-6. However, there is a lack of consistent implementation guidelines as in Austria.
The fire brigade uses mobile overpressure ventilators ( pressure ventilators ) in stairwells or escape routes in addition or alone in order to free them from smoke gases or to keep them smoke-free during tactical ventilation .
Meat counters
Meat counters in supermarkets often require overpressure ventilation to prevent germs from reaching the meat counter from the sales area. A constant flow of air should therefore be generated, which flows from the meat area into the public area.
military
The military uses overpressure in NBC protection systems to prevent the penetration of harmful substances.
literature
- Georg Schmidt: Die Rote Hefte, Booklet 203 - overpressure ventilation . 2., revised. Edition. Kohlhammer, Stuttgart 2007, ISBN 978-3-17-019596-7 .
- User guide and FAQs on smoke protection pressure systems (RDA)
