design &
facilities Management
If a new
approach is
understood to
have improved
efficiency or
stability, then it
is best to have
data to support
and substantiate
this claim.
Continuing to
develop first class
facilities requires
a continual
investment in
due diligence,
research and
development and
computational
simulation.
cold aisle of a computer room,
with many people still adamant
that the servers need to be kept at
sub-arctic temperatures, otherwise
terrible things will happen. A
gold standard for some time for
server inlet temperatures has
been the ASHRAE Envelopes,
recommending inlet temperatures
up to 27°C, and allowing up to 32°C.
However, as recent research
has shown and something ASHRAE
readily admit, is that maximising
these temperatures is also not the
single best way to go. You can – as
far as the servers are concerned –
go up to these temperatures, and
parts of the system will operate
much more efficiently because of
it, but that doesn’t mean that you
should. Importantly, if you consider
the system as a whole – cooling,
power and IT – then there is a point
of optimum operation past which
there are inefficiencies. With newer
IT systems, perhaps this optimum
point will change.
Eliminating fans from the
servers and instead demanding
a minimum pressure different
between hot and cold aisles would
change this substantially – this
is a great example of how a best
practice is hard to define in a
proudly innovative industry, and is
a great example of how continued
research allows the best practice
to change.
Discussion and debate
The great thing about this
industry is that we are not averse
to discussion and to debate.
Conversely, we actively embrace
it. As data centre designers and
operators, we want to make sure
that we are continually at the
forefront of innovation and best
practice, and we acknowledge
that a key to this is sharing of
knowledge and experiences.
This constantly changing,
dynamic environment, has one
downside which is often not
appreciated – confusion. There is
so much information about what is
right, what is better and what is the
best way of doing something that
it can be hard to filter the scientific
fact from the sales. You rarely
get the opportunity to have two
differing systems in a controlled
comparative test.
aligned with the requirements
of the equipment, and where
opportunities for passive cooling
are seized at every opportunity.
Similarly, uninterruptible
power supply (UPS) systems
have developed, and the options
available have widened, to align
better with the power qualities
present, and with the input power
characteristics which are required
by the systems. Efficiencies in
UPSs have developed to be nearly
lossless in some conditions. All of
this, however, has needed change.
It has taken many years for
people to change their mindset
about the temperature within a
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