Saturday, 20 June 2015

A Data Centre without fire risk?

An interesting system at IFSEC 2015 was Wagner's Oxyreduct system. This system can be used to protect Data Centre rooms, vaults, document storage rooms from fire. It works by increasing the proportion of nitrogen in the atmosphere until the oxygen proportion is 15% rather than the normal 20%.  At the 15% level there's insufficient oxygen to support normal combustion. They are classed as Hypoxic Air Fire Prevention systems. In classic fire risk training you learn about the Fire Triangle; you need all three sides Oxygen, Fuel, Heat to sustain combustion. Remove one of the sides and fire will not take hold. This technique takes out the oxygen side of the triangle.

I was invited into a demonstration room by the salesman where the Oxyreduct system was controlling the atmosphere. In a classic sales type of demonstration he handed me a cigarette lighter then asked me to try to set fire to his jacket. I couldn't get a flame from the lighter, even though it had worked just fine outside the room. 

Fundamental to the system is a nitrogen concentrator unit which extracts nitrogen from the atmosphere. This nitrogen is then pumped into the room to be protected and the oxygen level monitored to be maintained at the magical 15% level. You don't need to hold compressed nitrogen in cylinders or store liquid nitrogen.

Obviously the cost of installation and operation needs to be considered but I can see this could be a highly effective system in a data centre environment. Most fire suppression system react after a fire has started. Those types of systems can cause the shut down of a room and may cause some damage themselves. Oxyreduct is definitely worth a look! 

You'd need to be sure the room to be protected is effectively gas tight and good air movement within the room to help maintain the oxygen/nitrogen balance. You'd need to ensure the gas porosity of the building structure such as walls does not exceed the capability of the system unit to provide nitrogen. If people routinely work in the room you'd need provision to replenish oxygen depleted by their breathing. 

Perhaps a simple blood oxygen saturation monitor (Oximeter) might be needed to reassure workers, particularly any person who has a compromised respiratory system. Here's some Health and Safety guidance and Wikipedia information here. In any event it might be wise to limit staff exposure to 2 hours in the reduced oxygen environment. Normally the 15% oxygen is fine for healthy workers, but some countries such as the USA OSHA Regs might prevent the use of such a system providing less than 19.5% Oxygen. Some other standards which apply are VdS 3527en and BSI: PAS 95:2011

I'd consider deploying this as a primary system with an alternate backup fire suppression system, such as high pressure water mist as a backup, but that it all depends on the safety/risk benefit cost equation. If someone wedges a door open or otherwise defeats the gas tightness of the protected area the Oxyreduct system, as with any other gas based system, would become ineffective.

Here's a video:

There's some general information on these hypoxic systems here.

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