Mark Hirst examines some of the issues and how to deal with them, and explains how, with a bit of forward thinking, almost any environment can benefit.For the world’s largest organisations, constructing a data centre is simply a case of buying land in a suitable location and building a bespoke facility on it. However, for most others the process involves the utilisation of existing space that was probably not originally designed for such a purpose. This brings with it a number of challenges to ensure that any installed equipment performs to the highest standards under the best possible operating conditions.Factoring inAchieving optimum space utilisation in a data centre is where things can get particularly tricky. For instance, while it might be possible to configure 200 fully populated racks and cabinets in 300m2, it should be remembered that a similar amount of space would also be needed to house items such as plant, UPS, switchgear, chillers and generators. A building’s layout can be an issue too. While installations in basements and lofts can be particularly problematic, they are not the only areas to have integral features such as low ceilings, beams, pillars, doors and non-parallel walls that must be designed around. In addition to these challenges, it is almost always necessary to build in room for expansion, so space to carry out moves, adds and changes (MACs) must also be factored in from the outset, as a failure to do so could prove costly in terms of time, money and effort. The ability to deal with these issues comes down to good planning. Whether configuring a new facility or retrofitting equipment into an established data centre, it is vital to carry out a comprehensive site survey to establish what can feasibly be achieved. Although accurate information means that operational effectiveness can be maximised and the right products installed at a price that falls within the budget, some data centre owners and managers are reluctant to provide relevant information through fear of a confidentiality breach. Although this is a legitimate concern, a data centre that is either over-specified or under-specified is undesirable, so the key is to be as precise as possible at the planning stage and be realistic about potential growth – even if it means sharing information under a non-disclosure agreement (NDA).Sealed unitAn increasingly popular way of configuring a data centre infrastructure that addresses all of the above issues, and more, is free form aisle cocooning. This advanced technology unites cost effective cabling and airflow system containment to create a single integrated solution that also has a low energy footprint. It supports an end-to-end edge beam infrastructure, supporting overhead panels above the aisle without being individually dedicated to any one rack. Whatever the particular dimensions of a data centre, climate and temperature will certainly need to be controlled. Recent research from DCD Intelligence found that the number of high-density cabinets in servers – those over 10kW per cabinet – as a proportion of total cabinets, increased by 8.5 per cent globally between 2012 and 2013 to 15.2 per cent.To deal with climate control, most aisle cocooning systems utilise cold aisle containment, which encloses the cold aisle and prevents the mixing of cold air and hot exhaust air. It ensures that climate control units are placed in a way that keeps the airflow path as short as possible, improves the efficiency of the computer room air conditioning (CRAC) system and limits the energy it demands, resulting in an overall power usage effectiveness (PUE) rating of as low as 1.1. Within row cooling (WIRC) units can also be used to offer close-coupled airflow, negating the need for long ducting runs or large powerful fan systems. When used in a free form aisle cocooning system, cold air emitted from the floor is sealed in and cooling air can only exit through the equipment for which it is intended. What’s more, components such as overhead panels and aisle end doors are fixed to the cabinet bay structure alone and not connected to the room structure. This means that MACs can be carried out uninhibited – even the swap out of complete racks and cabinets can be completed in a live, fully operational data centre, with no disturbance to cable raceway.Mix and matchBeing able to cocoon an aisle is important, as all data centre environments change over time. Just as the type of hardware used has evolved, so too have the cabinets and racks, and this means that a facility might now have products that are a mix of different depths, widths and heights. Also, although well designed for internal cable management, some manufacturers’ racks and cabinets tend not to work so well when sited alongside server cabinets. This inconsistent approach can play havoc with even the best cooling system. It can be a similar story when it comes to cabling and pipe work. What used to be controlled and well ordered might now be in a state of unmanaged cable chaos. Spot checkWhere legacy cabinet installations exist, free form aisle containment technology provides a cost-effective retrofit solution that maintains the integrity of the cold aisle, even when different makes and models of cabinets are in-situ. Making an aisle cocooning solution work with multiple vendors’ cabinets means it needs careful design and consideration of possible ‘day 2’ changes – something that usually requires the help of experienced experts.For example, cabinets with raised feet for levelling can create a backwash of air underneath them, while there may be gaps either down the sides or where there is missing equipment. Blanking plates should be used to cover these as part of any best practice policy and there are a variety of quick fit blank panels available, with no tools required to fit them. A retrofitted aisle containment system involves fixing the ceiling edge beams to the top of the cabinets, installing ceiling panels, fitting air skirts under and between the cabinets if necessary, and attaching the doors at both ends of the aisle. This ensures that the cold air emitted from the floor is sealed in and remains unaffected by hot exhaust air, while the cooling air can only exit through the equipment for which it is intended. This, in turn, has both short-term and long-term operational expenditure advantages.Your flexible friendAs previously stated, the true benefits of a free form aisle containment solution can only be fully exploited after a thorough site survey has been completed and the design and installation team has a good understanding of the future plans for a facility. Once this has been completed, free form aisle containment can be successfully applied to almost any environment.Cocoons can be configured to be anything up to 52U in height, meaning that they will be able to accommodate the largest server cabinets. Conversely in buildings with lower ceilings, they can be specified accordingly. When it comes to retrofitting, it always helps if the cabinets are the same height but in reality this is rarely the case, leading to ‘Manhattan skyline’ type appearance. Although a height difference of a few centimetres can be managed easily, a difference of a metre or more is increasingly common in older environments. The development of specially designed ceiling and side panels create a uniform height both sides of the aisle and provide a snug fit, which maintains the effectiveness of a cold aisle. Side sealing panels when used in conjunction with secure integrated cable trays and brush sealed raceway bridges add another level of protection to the infrastructure. It is also possible to use these panels around pillars and assimilate them into the overall design with minimal loss of floor space.If this is carried out properly it will result in a seamless system where the various configurations work perfectly together, rather than an ineffective ‘cut and shut’ installation.Protect and surviveDealing with the problem of safety and security within a free form aisle containment solution has now been addressed in a number of innovative ways.Automatic self-closing doors with keypads or biometric access control not only stop unauthorised access but also help keep the temperature in the cold aisle stable. Similarly, there is a growing trend towards high efficiency light emitting diode (LED) based occupancy lighting, which automatically turns on and off when required and can even be controlled remotely through a data centre infrastructure management (DCIM) system. When it comes to fire protection, active overhead panels open automatically in case of fire, allowing overhead fire suppressant to enter into the aisles, or smoke to be extracted. Meanwhile, the whole cocoon can be monitored on a 24/7 basis with a dedicated service panel that can house CCTV cameras.All bases coveredWhether just a few cabinets or hundreds are required, free form aisle containment offers a flexible, scalable and secure solution that is perfect for use in a wide range of environments due to its ability to negate some of the common problems encountered when integrating third party equipment. However, to maximise the potential of this technology, it is advisable to carry out an extensive site survey, understand any constraints, and choose a partner that can take these into account and configure the best possible solution.
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