Technical cleaning is unlikely to be at the top of any data center operator’s priority list. If it’s there at all, it’s probably only grudgingly so.
That’s not to say that, over time, the industry has learnt nothing: providers realized early on that contaminants in the air would damage IT hardware, that static-producing carpets had no place in a server room, and cables belonged in subfloors. They also realized that restricting access to data centers was a good idea for cleanliness - as well as security.
But even now, being meticulous is not a given: data center operators wanting to skimp on costs have been known to reduce the frequency of their cleans to a bare minimum.
And while most people’s attitudes have matured, said Mike Meyer, director of ABM Solutions’ data center maintenance business, contaminants are still making their way into data centers. Best practice can remedy this, he told DCD, but some operators still tend to cut a few corners here and there.
So what contaminants affect data centers? Particulates as small as half a micron (a millionth of a meter, or 1/400,000 of an inch), can damage servers, storage and networking equipment by causing them to overheat and short circuit.
These particulates can come from anywhere, from a visitor’s shoe soles to fragments eroded from the inside of air conditioning ducts or data hall walls, or dust from packaged items unwrapped inside the data center.
Tim Gentle, the general manager of technical cleaning company Australian IT Services, also regularly finds errant insects and lost critters that roam - or have ceased to roam - under the raised floors when on a job.
Another, perhaps less common source of damaging particulates are zinc whiskers. Zinc whiskers are fluff-like accumulations of micron-sized elemental zinc that grow on electroplated surfaces. They develop spontaneously when zinc atoms separate from the steel, pushing the coating away from the surface at a rate of 250 microns a year. Zinc is a good conductor, so when whiskers reach 500 microns, they become a threat to microcircuits, causing short circuits, voltage variances and signal disturbances.
Most commonly, they grow under older raised floors, whose underside is made of steel galvanized or electroplated with zinc to avoid rusting or oxidation.
Many data centers have removed their zinc coated raised floors, but zinc whiskers can still enter through other means, such as zinc coated cable baskets, nuts, bolts, steel conduits and metal railings.
ABM Solutions told us of 30 to 40 zinc whisker cleaning projects it had done in the last eight years. Recently, one customer reported 142 power failures caused by the metal particulates.
As the industry has learnt about whiskers and other issues, cleanliness has become part of the design process. Modular data centers, for example, are typically well sealed to keep contaminants out.
However, other considerations like operating costs and energy efficiency can worsen things rather than improve them. For instance, free cooling saves energy by using outside air to remove heat, but it means the data center is more prone to ingest particulates from the outside world. Examples of this include: sea salt from marine air, dust from leaves in the autumn, industrial pollutants hanging in the air, et cetera.