Vacuum ventilation
A negative pressure ventilation is a ventilation system , in a certain part of the building a negative pressure generated.
It is used when you want to prevent substances (e.g. gases or microorganisms ) from leaving a room. The people who work in such a room usually wear a protective suit that works with positive pressure.
Another use case are indoor swimming pools. The purpose of the negative pressure is to prevent the damp indoor swimming pool air from flowing into other parts of the building and causing moisture damage there.
Wooden roof trusses as well as structures with external walls in skeleton and timber frame construction are often equipped with internal vapor barriers to prevent moisture from penetrating the insulation layer. It is hardly possible to lay vapor barrier films completely airtight. In order to achieve additional protection against the ingress of air humidity, it is therefore advisable to provide ventilation devices in such buildings that tend to generate underpressure rather than overpressure.
