Creating the Green Data Centre
Simple Measures to Reduce Energy Consumption

The continued thirst for energy is a recurring story in news headlines every day. Global warming forecasts rising temperatures, melting ice and population dislocations due to accumulation of greenhouse gases in our atmosphere from use of carbon-based energy. There are strong arguments for and against the dire predictions of global warming, yet one fact is undeniable-over the past 10 to 20 years, the inhabitants of Earth are collectively consuming more energy at a faster rate than ever before. No where is this more apparent than in the Data centre where power consumption has doubled in the past five years and is expected to rise at a steeper rate of 76% from 2005 to 2010. One culprit is steadily increasing power requirements for servers. For example, according to IDC (2006), the average small to medium size server required 150 W of power in 1996. These small to medium servers will require over 450 W by 2010. Of course, increased power requirements means increased heat to dissipate, driving another culprit for
increased energy use in the Data centre-cooling. One survey of IT executives shows that 45% of Data centre energy consumption goes to chiller/cooling towers and computer room air conditioners (CRACs). According to IDC 2006, in the year
2000, for every $1 spent on new servers, 21 cents was spent on power and cooling. By 2010, IDC predicts that every $1 spent on new servers will require 71 cents on power and cooling.
Initial results from the IDC's ongoing Asia/Pacific Green Poll - end-user surveys assessing the buying behavior of IT executives with respect to Green IT in the Asia/Pacific region - highlights that end-users will be expecting vendors to take more responsibility in terms of bringing 'Green' products and services to market
"This is validated by the fact that 81% of organizations thought that the 'Greenness' of their IT suppliers would become 'much more important' over the next few years. Today, 18% of the organizations surveyed considered the greenness of the IT suppliers before making a selection and another 30% expected to do so in the near future."
Furthermore, organizations in the more developed economies are looking to integrate 'green requirements' into 'requests for proposals' for procurement of IT products and services.
According to IDC’s observation the first phase of the Green IT adoption will be about 'Lean IT' - focusing on improving energy efficiency of IT equipment within the Data centre to reduce costs in the face of rising electricity costs
in emerging economies like India it is very clear that cost savings is the primary driver for investment in Green IT, followed by Corporate Social Responsibility.
For some businesses, increased energy costs are merely considered a cost of doing business. Yet there is a point at which these costs dampen profits and limit investment needed to grow and modernize a business. Worse are shortages of
electricity in India that prohibit businesses from expanding Data centre operations to keep pace with their growing company.
In practice, a Data centre may be able to reduce the number of servers from 70 to 45, for example. Virtualization recognizes that a server gives off 100% of its heat if it is 20% or 90% in use. This dramatically reduces power and cooling costs across the Data centre.
Yet there are many other ways to reduce power and cooling costs in the Data centre-ways that are far simpler and less expensive to implement.
Airflow Management in Cabinets
New server platforms can support 800 to 1,000+ optical fibre terminations or 600-1000+ copper cable terminations per chassis. The prospect of crowding too many cables into vertical managers poses a problem for thermal management in cabinets. When air cannot properly circulate in the cabinet, Data centre fans are called upon to move more air and cooling units to lower air temperature-both of which consume additional, unnecessary electricity.
For years the IT industry has promoted the benefits of increased rack and cabinet density. Servers are smaller than ever and more can fit into the same space. The rationale has always been to make the best use of Data centre floor space. Yet
today the balance is shifting. New servers are consuming more energy than ever before, causing Data centre and facilities managers to weigh spiking operating costs due to more energy usage against the capital cost of “wasted” space of lower density configuration in raised floor environments. Instead of just focusing on density, energy efficiency demands that Data centre and facilities mangers look at managed density. Managed density recognizes that there really is a limit to the number of cable terminations and servers that can safely and economically be housed in cabinets. A prime issue is potential blocking of airflow caused by too many cables within the cabinet. One solution is to limit the number of servers and
cable terminations in a cabinet, especially in copper racks where cable diameter is larger. Another is to employ basic cable management within the cabinet, such as securing cables along the entire length of vertical cable managers to open airflow. Similarly, integrated slack management systems locate and organize patch cords so that maximum space is available for flow of cool air into and out of the cabinet.
Using smaller diameter copper cable is another means to improve airflow within the cabinet. For many Data centres, copper equipment terminations are still prevalent, especially with the ability to push 10Gb/s over Augmented Category
6 cabling. The choice of copper cabling can impact airflow because some cables have a much smaller outside diameter. For example, ADC KRONE’s AirES technology provides superior conductor insulation that allows cable to exceed standards for electrical performance using smaller gauge copper and less insulating material. The result is cable with an average outside diameter that is 28 to 32 percent smaller than standard Category 6 or Category 6A cables.
Airflow Management in the Data centre
There are many simple solutions to improve overall airflow efficiency in the Data centre that can be implemented immediately, and without major changes in the design and layout of the Data centre. In general, unrestricted airflow requires less
power for cooling efforts. Each incremental improvement results in less energy to cool equipment-reducing costs and limiting output of greenhouse gases from the power company. These simple solutions include the following:
Plug unnecessary vents in raised floor perforated tiles.
- Plug other leakages in the raised floor by sealing cable cutouts, sealing the spaces between floors and walls, and replacing missing tiles.
- Reduce air leakage by using gaskets to fit floor tiles more securely onto floor frames
- Ensure that vented floor tiles are properly situated to reduce hot spots and wash cool air into equipment air intakes.
- Manage heat sources directly by situating small fans near the heat source of equipment.
- Use time of day lighting controls or motion sensors to dim the lights when no one is in the Data centre; lights use electricity and generate added heat, which requires added cooling.
- Reduce overall Data centre lighting requirements by using small, portable lights within each cabinet, which puts light where technicians
need it.
- Turn off servers not in use.
There are also many avenues for improving data airflow that require more planning and execution. The most documented and discussed is the hot aisle/cold aisle configuration for cabinets.

Designing hot aisle/cold aisle presents its own set of challenges, including the following:
- Ensuring that cool air supply flow is adequate for the space
- Sizing aisle widths for proper airflow
- Positioning equipment so hot air does not re-circulate back into equipment cool air inlets
- Adding or removing perforated floor tiles to match the air inlet requirements of servers and other active equipment
- Accounting for aisle ends, ceiling height and above cabinet blockages in airflow calculations
Another ready means to improve cooling is removing blockages under the raised floor. The basic cable management technique of establishing clearly defined cable routing paths with raceway or cable trays under the floor keeps cables organized, using less space and avoiding the tangled mess of cables that can restrict airflow. Moving optical fiber cables into overhead raceway as well as removing abandoned cable and other unnecessary objects from below the floor also improves airflow.
Dust and dirt are enemies of the Data centre. Dust has a way to clogging equipment air inlets and clinging to the inside of active equipment. All of this dust requires more airflow and more cooling dollars in the Data centre.
Selecting Green Cable
It was shown earlier that cable made with AirES conductor insulation is smaller in diameter and therefore contributes to improved airflow and reduced energy costs. Yet for the truly environmentally conscious individual, copper cable made with
AirES technology offers another important benefit-less material is used for cable construction. By combining channels of air with traditional FEP insulation material, the net effect of AirES is superior electrical performance and smaller outside cable diameter. Yet the AirES cable is 28 to 32 percent smaller because there is simply less copper and FEP used in the cable manufacturing process. For every 1,000 feet of cable made with AirES conductor insulation, 1.45 fewer pounds of FEP insulation and 1.25 fewer pounds of copper are required. This may not make
a difference today that can be verified. However, cable made with less insulation and copper will have less impact on the landfill for installation scrap and when the cable is abandoned. For recycled cable, less material requires less energy for the
recycling process, too.
ADC KRONE’s subject matter expertise with infrastructure upgrades can result in major benefits to those managers often focusing on things seen as bigger ticket items than infrastructure. But the savings and benefits cannot be denied. According to IBM, infrastructure upgrades can result in cooling cost savings of
15 to 40%. Data centre engineers and designers can leverage ADC KRONE’s product and design expertise to reap these types of immediate benefits, allowing them to focus on other areas critical to cost and energy savings, as well as pending site certification.
Conclusion
There are many ways to reduce cooling requirements for Data centres. Improving cable management, stopping air leakages, removing cable dams under the floor, choosing smaller diameter cable to improve airflow are just a handful of the
measures available to Data centre planners and managers.
Any Green Initiative that conserves energy and saves money makes sense from many angles, especially for the power hungry Data centre: improved work environment for people and equipment, corporate commitment to community and environment, improved operating costs from reducing energy consumption.
ADC KRONE supports green Data centres by designing and manufacturing solutions for passive airflow improvement that reduce cooling-and power-requirements.
A well planned infrastructure will make a tremendous difference and ADC KRONE can get you there today.
For more information contact ADC KRONE on
1-800-425-8232, visit www.adckrone.com/in
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