Temp at Level 3 data centers

Jean-Francois Mezei jfmezei_nanog at vaxination.ca
Thu Oct 12 23:56:14 CST 2017

back in the arly 1990s, Tandem had a computer called "Cyclone". (these
were mission critical, fault tolerant machines).

The reason for "Cyclone" name was that the cabinets had huge fan
capacity, and that was to deal with air conditioning failure by
increasing the air flow over the electronics to still keep then "comfy"
despite high data centre air temperature. (with the aim of having the
Tandem continue to run despite HVAC failure).

With dense  computers packed in 1U, you just can't have that excessive
airflow to cope with HVAC failure with tiny 1" fans.

The other difference is data centre density.  Bank computer rooms were
sparse compared to today's densely packed racks. So lots of space
relative to heat sources.

The equivalent today would be the football field size data centres from
the likes of Google with high ceilings and hot air from one area with
failed HVAC to rise to ceiling and partly be taken out by the others.

But when you are talking about downdown co-lo with enclosed suites that
are packed to the brim, failure of HVAC results in quick temp increases
because the heat has nowhere to spread to, and HVACs from adjoining also
enclosed suites can't provide help.

So when a tennant agrees to rent rack space in an small enclosed suite,
it should be considerewd that the odds of failure due to heat are
greater (and perhaps consider renting rack space in different suites to
provide some redundancy).

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