User Manual

42
Siemens Switzerland Ltd
Building Technologies Division
5.5.1. Areas requiring special attention
When planning the extinguishing concept for a historical building or museum, the following areas should be given
special attention:
· Archives
· Electrical plant rooms
· Kitchens
Archives A system employing a combination of gas and water mist can provide an
effective solution for archives and storage vaults, in which documents,
manuscripts, books or paintings are stored.
The high concentration of flammable and very valuable artifacts implies that any
incipient fire must be detected as early as possible and effectively suppressed,
without the extinguished agent used causing any further damage to the stored
objects. As archives often consist of multiple rooms, the fire protection
infrastructure should also ensure that a fire in one room cannot spread to an
adjoining room or to any other part of the building.
Aspirating smoke detection systems (ASD) are able to detect even the smallest
aerosol concentrations and offer the ideal solution for fire detection in archives
and storage vaults. An alarm from such a system can be used to automatically
activate an extinguishing system. Extremely good results have been achieved by
using a mixture of nitrogen together with a fine water mist. The nitrogen
effectively reduces the oxygen content of the room atmosphere, while the water
mist provides additional cooling and prevents re-ignition, without causing
damage to the stored artifacts.
Electrical plant rooms A gas extinguishing system provides efficient fire protection for electrical and
electronic installations. This would be an appropriate solution for the protection
of server rooms, particularly as no residues are left behind after an extinguishing
incident and fire damage can be restricted to an individual piece of equipment.
Such systems are very effective in putting out fires and preventing re-ignition,
allowing normal operation to be resumed as quickly and smoothly as possible.
Standard applications include centralized systems and modular systems. In a
centralized system, all gas cylinders are installed in a central location outside the
protected zone and preferably in a dedicated storage room. Centralized systems
always require a site-specific design, as all pipe diameters and nozzles must be
calculated individually according to the particular application.
Figure 19 Modular and centralized extinguishing systems
Modular systems, on the other hand, consist of space-saving compact units that
are installed within the protection zone itself. These units combine fast and
reliable detection with quiet and safe extinguishing in one compact package.
Such systems are particularly suitable for the protection of small enclosures with
volumes up to 132 m
3
that contain electronic and electrical equipment. The main
cost-saving advantage of such systems is that they can be installed quickly and
easily, and service and maintenance costs are very low.