[AusNOG] Hypoxic Fire Suppression [was Global Switch]

[Tony de Francesco]

Just to clarify the australian BCA requirements: all habitable spaces
including machine rooms, switchrooms, etc. must be provided with fresh
outside air. The levels required are stipulated in AS1668 but typically
work out at around 1 l/s per m2 for most data centre spaces.

Hospital operating theatres are actually provided with 100% outside air via
HEPA filtration with surrounding service corridors kept at approx -ve 20Pa
pressure to ensure that no "dirty" air enters the theatre.

Even if it was not a BCA requirement there is a need for fresh outside air
in a data centre keep ot at a higher pressure than surround areas to ensure
that "dirty" air does not enter the technical space.

Regards

Tony de Francesco
Technical Director
P.U.E. Pty Ltd
Mob: +61 (0) 457 701 179
Email: tonyd at pue.com.au
On 13/01/2014 8:13 PM, "Matt Perkins" <matt at spectrum.com.au> wrote:

>  That's good info Bevan,
> I wonder if the building code requires that fresh air be injected into the
> entire building or all rooms within the building. I wonder if Hypoxic fire
> prevention could be employed in small computer room type environments or
> data centers where division into smaller rooms or where cold/hot aisle for
> example. I guess not useful  information for centers with large floor
> plates but may be useful in power room environments or small server rooms
> etc.  If the building code allows.
>
> Operating theaters for example dont have fresh air injected into them.
> It's a highly filtered air that's injected from the outer rooms surrounding
> the theater through HEPA and active charcoal.  What counts as fresh air.
>
> These guys make an interesting device.
> http://altitudetraining.com/prevenex/products/airunit
>
> Matt.
>
>
>    On 13/01/14 7:07 PM, Bevan Slattery wrote:
>
>
>
>  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 DC’s 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 couldn’t 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
> “significant”.  Very significant.
>
>  All in all it wasn’t 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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