Thursday, 15 February 2018

Humidity Control + Energy Saving: is there a solution?

ASHRAE has been working for many years on guidelines that allow a wider tolerance for temperature and humidity. Consequently, the need to humidify has decreased, making the value of humidification equipment less significant in the overall HVAC system of the DC.

However, what if maintaining the humidity also reduced the cooling demand?

One of the most effective solutions involves the use of adiabatic humidifiers: adding moisture to an air stream, absorbing heat in the air, increasing humidity and decreasing the temperature for very little energy consumption (c.1kW electrical power for 70kW cooling)

This evaporative cooling is increasingly used in new generation data centres in which the design conditions are close to the limits suggested by ASHRAE: this is made possible by careful design of air flows and good separation between the air entering the racks and the exhaust air (layout with “hot aisles and cold aisles”).

The higher operating temperature and humidity allow the use of outside air for ‘free cooling’ (e.g. when below 25°C), and when the outside air is hotter and drier, evaporative cooling can be adopted, increasing humidity up to 60% and higher while bringing the temperature down to acceptable values, simply through the evaporation of water.

There are several different adiabatic humidification technologies available, from “wetted media” to washers and spray systems: the principle underlying all of these devices is to maximise the contact surface area between air and water, so as to ensure effective evaporation and perfect absorption in the humidified air stream. The choice of the system depends on numerous factors, ranging from available space to required efficiency and the need for modulation.

In general, the solution needs to be evaluated in terms of TCO (Total Cost of Ownership) throughout the system’s working life, also taking into consideration its resilience in terms of continuous operation as well as water consumption, which in many areas may be a critical factor: indeed, many data centres, together with the classic PUE (Power Usage Effectiveness) for energy consumption also monitor WUE as regards water consumption.

Recently, atomisation systems have become quite popular; these use a system of nozzles and high pressure pumps to create minute droplets of water, thus ensuring optimum absorption. These systems can be controlled by inverters to modulate atomised water production and respond to different load conditions. Other benefits of these systems include very low air pressure drop, no recirculation (and consequently a high level of hygiene, something that unfortunately is often neglected) and the possibility to use one pumping unit with two separate distribution systems; one for summer (evaporative cooling) and one for humidification in winter, meaning significant flexibility - even with vertical air flows.

The effectiveness of such systems depends significantly on local temperature-humidity conditions and in much of Europe both free cooling and evaporative cooling can be exploited for most of the year, to the extent where some data centres are designed to use mechanical cooling as an emergency backup system only.

Guest blog written by Enrico Boscaro, Group Marketing Manager and William Littlewood, Business Development manager, Carel

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Wednesday, 3 January 2018


CNet Training recently welcomed Alexander Taylor, an anthropology PhD student from the University of Cambridge, onto its Certified Data Centre Management Professional (CDCMP®) education program. Alex recently researched the practices and discourses of data centres. In this article, he outlines his research in more detail and explains how the education program contributed to his ongoing anthropological exploration of the data centre industry.

Data Centres as Anthropological Field-sites

Traditionally, anthropologists would travel to a faraway land and live among a group of people so as to learn as much about their culture and ways of life as possible. Today, however, we conduct fieldwork with people in our own culture just as much as those from others. As such, I am currently working alongside people from diverse areas of the data centre industry in order to explore how data centre practices and discourses imaginatively intersect with ideas of security, resilience, disaster and the digital future.

Data centres pervade our lives in ways that many of us probably don’t even realise and we rely on them for even the most mundane activities, from supermarket shopping to satellite navigation. These data infrastructures now underpin such an incredible range of activities and utilities across government, business and society that it is important we begin to pay attention to them.

I have therefore spent this past year navigating the linguistic and mechanical wilderness of the data centre industry: its canyons of server cabinet formations, its empty wastelands of white space, its multi-coloured rivers of cables, its valleys of conferences, expos and trade shows, its forests filled with the sound of acronyms and its skies full of twinkling server lights.

While data centres may at first appear without cultural value, just nondescript buildings full of pipes, server cabinets and cooling systems, these buildings are in fact the tips of a vast sociocultural iceberg-of-ways that we are imagining and configuring both the present and the future. Beneath their surface, data centres say something important about how we perceive ourselves as a culture at this moment in time and what we think it means to be a ‘digital’ society.Working with data centres, cloud computing companies and industry education specialists such as CNet Training, I am thus approaching data centres as socially expressive artefacts through which cultural consciousness (and unconsciousness) is articulated and communicated.

The Cloud Unclothed

CNet Training recently provided me with something of a backstage pass to the cloud when they allowed me to audit their CDCMP®data centre program. ‘The cloud’, as it is commonly known, is a very misleading metaphor. Its connotations of ethereality and immateriality obscure the physical reality of this infrastructure and seemingly suggest that your data is some sort of evaporation in a weird internet water cycle. The little existing academic research on data centres typically argues that the industry strives for invisibility and uses the cloud metaphor to further obscure the political reality of data storage. My ethnographic experience so far, however, seems to suggest quite the opposite; that the industry is somewhat stuck behind the marketable but misleading cloud metaphor that really only serves to confuse customers.

Consequently, it seems that a big part of many data centres’ marketing strategies is to raise awareness that the cloud is material by rendering data centres more visible. We are thus finding ourselves increasingly inundated with high-res images of data centres displaying how stable and secure they are. Data centres have in fact become something like technophilic spectacles, with websites and e-magazines constantly showcasing flashy images of these technologically-endowed spaces. The growing popularity of data centre photography – a seemingly emerging genre of photography concerned with photographing the furniture of data centres in ways that make it look exhilarating – fuels the fervour and demand for images of techno-spatial excess. Photos of science fictional data centre-scapes now saturate the industry and the internet, from Kubrickian stills of sterile, spaceship-like interiors full of reflective aisles of alienware server cabinets to titillating glamour shots of pre-action mist systems and, of course, the occasional suggestive close-up of a CRAC unit.One image in particular recurs in data centre advertising campaigns and has quickly become what people imagine when they think of a data centre: the image of an empty aisle flanked by futuristic-looking server cabinets bathed in the blue light of coruscating LEDs.

With increased visibility comes public awareness of the physical machinery that powers the cloud mirage. This new-found physicality brings with it the associations of decay, entropy and, most importantly, vulnerability that are endemic to all things physical. As counterintuitive as it may seem, vulnerability is what data centres need so that they may then sell themselves as the safest, most secure and resilient choice for clients.

Some (Loosely Connected) Social Effects of Cloud Culture

The combination of the confusing cloud metaphor with the almost impenetrable, acronym-heavy jargon and the generally inward-looking orientation of the data centre sector effectively black boxes data centres and cloud computing from industry outsiders. This means that the industry has ended up a very middle-aged-male-dominated industry with a severe lack of young people, despite the fact that it’s one of the fastest growing, most high-tech industries in the UK and expected to continue to sustain extraordinary growth rates as internet usage booms with the proliferation of Internet-of-Things technologies. This also makes data centres ripe territory for conspiracy theories and media interest, which is another reason why they increasingly render themselves hyper-visible through highly publicised marketing campaigns. You often get the feeling, however, that these visual odes to transparency are in actual fact deployed to obscure something else, like the environmental implications of cloud computing or the fact that your data is stored on some company’s hard drives in a building somewhere you’ll never be able to access.

Furthermore, while cloud computing makes it incredibly easy for businesses to get online and access IT resources that once only larger companies could afford, the less-talked-about inverse effect of this is that the cloud also makes it incredibly difficult for businesses to not use the cloud. Consider, for a moment, the importance of this. In a world of near-compulsory online presence, the widespread availability and accessibility of IT resources makes it more work for businesses to get by without using the cloud. The cloud not only has an incredibly normative presence but comes with a strange kind of (non-weather-related) pressure, a kind of enforced conformity to be online. It wouldn’t be surprising if we begin to see resistance to this, with businesses emerging whose USP is simply that they are not cloud-based or don’t have an online presence.

And the current mass exodus into the cloud has seemingly induced a kind of ‘moral panic’ about our increasing societal dependence upon digital technology and, by extension, the resilience, sustainability and security of digital society and the underlying computer ‘grid’ that supports it. Fear of a potential digital disaster in the cloud-based future is not only reflected by cultural artifacts such as TV shows about global blackouts and books about electromagnetic pulse (EMP), but is also present in a number of practices within the data centre industry, from routine Disaster Recovery plans to the construction of EMP-proof data centres underground for the long-term bunkering of data.

Closing Acknowledgments

With the help of organisations like CNet Training I am thus studying the social and cultural dynamics of data-based digital ‘civilisation’ by analysing the growing importance of data infrastructures. Qualitative anthropological research is participatory in nature and, as such, relies upon the openness of the people, organisations and industries with whom the research is conducted. Every industry has its own vocabularies, culture, practices, structures and spheres of activity and CNet Training’s CDCMP®program acted as a vital window into the complexity of data centre lore. It provided me with a valuable insider’s way to learn the hardcore terms of data centre speak and also with the opportunity to meet people from all levels of the industry, ultimately equipping me with a detailed, in-depth overview of my field-site. Interdisciplinary and inter-industry sharing of information like this, where technical and academically-orientated perspectives and skills meet, helps not only to bridge fragmented education sectors, but to enable rewarding and enriching learning experiences. I would like to sincerely thank the CNet Training team for assisting my research. 

Guest blog by Alexander Taylor, PhD Candidate with the Department of Social Anthropology at the University of Cambridge

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