Fire Safety

In order to protect equipments and contents of a data centre, we have to use a fire system with early detection and harmful to IT components.

In a building housing a data centre, there are two types of fire risks[1]:

Class A: Risk of smouldering in computer and electrical rooms. Usually caused by overheating of an electronic component or cable, the "smouldering" generates significant smoke which is harmful to the installed hardware and early detection can cause a flashover.

Class B: Open fire at the generators responsible for ensuring continuity of supply in case of power failure. The "open fire" refers to the rapid combustion flame phenomenon: at this stage, a rapid response is needed to limit the damage in the building. This risk is particularly due to flammable liquids present within the generators.

Detection

Fire detection in a data centre is primarily aimed at detect fire at the earliest, from his "smouldering" phase. So it is the presence of smoke that is sought primarily by the device.

So we choose to use a multipoint VESDA [2] (Very Early Smoke Detection Apparatus) by aspiration and laser technology which allows smoke detection at very high sensitivity and it’s adapted to environment as false floor or ceiling, as well as cable trays or confined space.

Figure 1 : Detection System VESDA

Extinction by INERT Gas

The detectors are connected to an electrical control device which incorporates a delay fire alarm unit (identification of the alarm zone) and pilot the extinguishing system.[3]

We choose extinction by inert gas which is composed of; Co2, Nitrogen and Argon, gases naturally present in the atmosphere.

The inert gas is the oldest substitutes for Halon and it has been safety tested on volunteers under medical supervision.It operates by lowering the oxygen level leading to smothering the fire.

Figure 2 : Composition of Inert Gas

Harmless to the ozone layer does not contribute to global warming and without atmospheric lifetime

Stored in compressed form it allows great flexibility in the choice of the location of the tanks and facilitates the use of remote directional valves and non-deported.

Producing no thermal shock, or condensation or mist or residue or decomposition product, it is also electrically insulating.

Harmless to humans even in hypoxic atmosphere because during the spreading, the ambient air remains breathable and is not flammable.

Figure 3 : Extinction by inert gas in the server

Figure 4 : Fire system installation

References

[1]Falck. (2014). Classes of Fire. Available: http://www.falckproductions.com/resources/fire-safety-and-firewatch/classes-of-fire-a-b-c-d-and-k/. Last accessed April 2015.

[2]Xtralis. (2014). Fire and Life Safety Solutions from Xtralis. Available: http://xtralis.com/o.cfm?o=411. Last accessed April 2015.

[3]Fire Suppression UK. (2014). Fire Suppression Systems. Available: http://www.firesuppression.co.uk/fire-suppression-systems-server-rooms.aspx. Last accessed April 2015.