[AusNOG] Hypoxic Fire Suppression [was Global Switch]

[Bevan Slattery]

From:  Tony de Francesco <tonyd at pue.com.au>

> Yes but Inergen is not used in large DCs because of the volume required.

Simply not correct.  Most large DC¹s segregate spaces to allow full
discharge in a specific area.
> The European system is a hypoxic system at low pressure. Very different to
dumping a whole bunch of gas through high pressure nozzles.

Challenge with this system in Australia (which I looked at early in NEXTDC
days) was that in Australia you need to continually supply fresh air to a DC
under the building code.  It is difficult to continually deliver a hypoxic
environment across a large facility considering the Australian standards and
the need to continually extract O2/Inject N2 into the air supply.

Hypoxic systems are typically used in things like ship engine rooms to
reduce the risk of catastrophic fire or in environments with low traffic
flow (archives).  In a colocation environment in Australia I couldn¹t get an
insurer to get their head around having staff and customers in a facility
with a reduced O2, let alone the technical issues around a requirement to
continually alter the air mix due to the building code.

So if you want to maintain a lower level of O2 you had to operate the Agent
Generator (essentially lower O2 in a bottle) 24/7 to maintain the O2 levels
at the Fire Type 2 levels.  The amount of fresh air required in a 20,000m
facility that had a volumetric size of 100 megalitres is ³significant².
Very significant.

All in all it wasn¹t technically or commercially viable for NEXTDC at the
time to provide a continuous hypoxic environment.  This may have changed.
There was some investigation into using an agent generator to create the
refill in case of discharge removing the need for a refill from alternate
gas suppliers.  But the equipment needed to refill 20 megalitres (hall
discharge +1) was significant and the bottles required was considerably
greater from memory.  Also not all gas discharge systems are as high
pressure these days so you may want to check out the latest to ensure your
points are valid.

Cheers

[b]








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