Dead Certain

October 14, 2015

David Hogg of 8 Solutions says that data centres are often a victim of their own environment.

Dust is an insidious beast. Its official definition is ‘tiny particles of earth or waste matter lying on the ground, on surfaces, or in the air.’ Wherever it is found, it can cause untold damage to sensitive equipment, especially within a data centre.

But where do dust and other potentially damaging contaminants come from? How can their sources be identified? And how can the environment in which a data centre is built impact on the amount – and the type – of contaminants that are generated?

‘Dust’ and other equally damaging contaminants can emanate from various sources, the most obvious being dead skin or clothing deposits or, in the case of being situated close to the coast, salt from the sea air.  But they can also stem from far less obvious sources.

In attempting to reduce the cost of cooling, for example, some data centres are inclined towards drawing in direct air form the outside that needs to be filtered. Ironically, this often introduces chemicals into the cooling process, and this in turn can lead to contaminants such as calcium being created from evaporative cooling. In the same way that white calcium is created on a filament in a domestic dishwasher or kettle, so too are such deposits created in modern air conditioning systems, with potentially more damaging consequences.

Air conditioning systems are indeed a significant source of contaminant. Some of the older units, for example, include a rubber belt as part of the drive mechanism, and over time this can shed material that can compromise an otherwise pristine clean room environment.

Outside source

Outside sources can also lead to contamination. Data Centres that are built too close to the coast, as highlighted, may suffer from salt contamination and corrosion. Buildings that are close to heavy industrial sites, or those with significant numbers of large vehicles, can be impacted by carbon and diesel emissions. And there is even one case recently where a client was being plagued by a mysterious ‘black dust’ whose source was finally traced to a nearby crematorium!

Uncovering and discovering sources of contamination is a challenge. It is not uncommon, for example, for a data centre to believe that the contamination comes from one source, to find – after testing – that the contamination stems from another source altogether, and one that the data centre management had never even considered.

Sometimes they are simply looking in the wrong place: contaminants that one might expect to be found in the air conditioning ducting, for example, may not be there, but not because the source of contamination is wrong, but rather that the contaminants have already dispersed.

So-called ‘unexplained contamination’ requires a better understanding of the environment, and intelligent analysis of the data presented. By taking away samples and testing them in an independent laboratory, the mystery of the ‘unexplained’ can invariably be explained, and the impact of contaminants properly measured. Technical cleaning of course has its place; but technical cleaning without recognising and understanding the source of contamination, is effectively throwing good money after bad.