User Manual

Fire Safety
58
Building Technologies 049_Archives_and_Libraries_A6
V10271399_a_en.doc
Fire Safety & Security Products 03.2009
tration of extinguishing agent and therefore reducing the very success of the extin-
guishing system.
4.4.8 Room Integrity, retention time and Door-Fan Test
Retention time
Room integrity of the protected area is a key issue. A leaky enclosure will not retain
the extinguishing agent for long enough, so the fire could reignite. Failure to
achieve the retention time is not a failure of the extinguishing system; it’s a failure
of the customer’s enclosure.
Very few enclosures are entirely airtight. Cabling, ventilation, lighting and other
systems could be connected to the protected volume; there small gaps are likely to
occur:
– around doors and windows
– where stud walls join the floor and ceiling
– at cable entries
– through the floor and ceiling tiles
– into light fittings
– into power points
– through plasterboard
Obvious visible leaks (e.g. at cable entries) can be sealed, others may be impossi-
ble to locate or seal.
Room preparation
When a room is being prepared to host an extinguishing system, some key integ-
rity aspects have to be taken into account:
– All windows have to be fixed closed or automated to be operated by the extin-
guishing control system, before the extinguishing agent is released.
– Doors have to be automated (magnet device or similar) to automatically closed
by the extinguishing control system, before the extinguishing agent is released.
These aspects are mandatory according to VdS in Germany, and strongly recom-
mended for all systems in the rest of the countries.
Door-Fan-Test
Rooms in archives and libraries to be protected with extinguishing systems, are in
the majority of the cases conceived in already existing buildings. This is often the
case in historical buildings, and means that often rooms present many “natural
leakages”.
Being the tightness of the room the key factor to assure the extinguishing agent
concentration build-up, Siemens strongly recommends that Door-Fan-Tests are
performed before installing the extinguishing system and then regularly once a
year or after modifications or renovations.
The Door-Fan-Test offers a simple, cost-effective and environmentally friendly
method for measuring room tightness. To test a room, a fan is placed in the en-
trance door. It blows air into the extinguishing area or removes air from the room,
creating an overpressure or partial vacuum of approx. 50 Pa, and allowing any
leaks to easily be located.