User Manual
37
Siemens Switzerland Ltd
Building Technologies Division
5.3. Extinguishing systems
The most appropriate automatic extinguishing systems for historical buildings and museums depend to a large
extent on the application.
· In general exhibition areas
o Sprinkler systems
o Water mist systems
· In archives, closed storage vaults and electrical plant rooms
o Gas extinguishing systems
o Extinguishing systems using gas/water-combined technology
5.3.1. Sprinkler systems
These automatic systems use water as the extinguishing agent and provide a very effective protection both for
property and human life. The advantages of sprinkler systems are their high reliability and wide application
spectrum in the protection of people and material assets. Not only do they stand out due to their relatively simple
and robust technology, there is generally a plentiful supply of the extinguishing agent – water.
Very often the primary fire protection provision is the water sprinkler system, either wet pipe or pre-action
arrangements as per NFPA 75 code. Such systems are intended to protect the integrity of the building structures
and prevent their collapse. In effect, the purpose of sprinkler systems is to control the fire and to cool the building
infrastructure in order to allow firefighters to reach the fire location and to perform their duty.
Sprinkler systems are common in modern purpose-built museums and are required by local building regulations in
many countries. The installation of sprinkler systems in historical buildings and museums, however, is somewhat
frowned upon for a number of reasons. Of course the installation procedure is quite invasive and can only be
considered when the sensitivity of the building allows it. However, the advantages are considerable as sprinklers
are very effective in preventing a fire from spreading to other areas of a building. It is a common misconception
that all sprinkler heads are activated simultaneous and not just the one(s) in the immediate vicinity of the fire. Any
water damage caused by a sprinkler system is very limited as over 80% of all fires can be controlled by only 1 or 2
sprinklers. This is in stark contrast to water damage that can be caused by fire brigade water hoses. Although
accidental activation of a sprinkler is often quoted as an additional and unwarranted risk, this is a very rare
occurrence (statistically shown to be in the million-to-one region).
It is also feasible to install a sprinkler system quite unobtrusively in historical buildings and museums. Concealed
sprinkler heads can be made almost invisible, being hidden by cover plates painted the same color as the ceiling. If
this type of sprinkler head is used, however, care must be taken to ensure that they do not get painted shut
during any subsequent redecoration exercise. The cover plate also means that the reaction time may be
negatively affected. Alternatively, various types of wall mounted sprinkler heads are available, which can also
provide a discreet installation and the small bore plastic piping can often be hidden from view by utilizing cornice
moldings and the voids behind the paneling.
Further advantages:
· Installation of a sprinkler system can significantly reduce insurance costs
· Sprinklers only extinguish areas which need to be extinguished
· Sprinklers outside the fire source remain closed
· Extinguishing water released reduces smoke and dangerous gases
· The cooling effect of extinguishing water increases the safety of rescue forces
· Low maintenance costs
· Robust and very reliable
Sprinkler systems consist of a network of water pipes with sprinkler heads positioned in such a way that (in case of
fire) all areas to be protected would be reached by the extinguishing water spray. The sprinkler heads react
individually to heat, opening to discharge a pressurized water spray when the temperature is sufficiently high. In