Insight and analysis on the data center space from industry thought leaders.

Improving Energy Efficiency in Data Centers

With the high costs of power, energy efficiency has rapidly become a critical consideration when evaluating data centers. It is, perhaps, second only to performance when deciding upon data center facility and information technology (IT) network design.

Industry Perspectives

April 28, 2011

3 Min Read
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Peter Sacco, founder and president of PTS Data Center Solutions, is a recognized expert in data center, computer room, and network operations design. He also posts on PTS Blog

Peter Sacco

Peter Sacco

PTS Data Center Solutions

With the high costs of power, energy efficiency has rapidly become a critical consideration when evaluating data centers. It is, perhaps, second only to performance when deciding upon data center facility and information technology (IT) network design. Higher energy consumption is a recurring cost that can add dramatically to operating expense over time. Furthermore, devices that consume more power require more cooling which not only further increases energy costs but impacts the physical design of the data center.

Energy Efficiency Assessments

Data center designers, manufacturers of data center facility infrastructure, and IT infrastructure manufacturers have recently flooded the market with estimated energy efficiency savings through the use of various facility and product design techniques. It is best practice to validate these claims by performing Energy Efficiency Assessments. These assessments are completed by performing spot measurements and calculations of a site's Power Usage Effectiveness (PUE) and Data Center Infrastructure Efficiency (DCiE) ratios. These measurements allow data center consultants to compare the data center against industry standards to estimate the energy efficiency of the facility. In fact, the assessment of these ratios helps determine where the most potential exists for substantial cost savings.

Developing an Action Plan

Once an initial assessment is completed, a systematic plan and analysis leads to a series of recommendations available to improve energy efficiency and consumption in the facility without sacrificing performance or availability. The intent is to verify the most significant energy savings measures that can be implemented to reduce energy consumption and then building and implementing an action plan to complete these measures.

Lessons Learned - Greening the Data Center

Ultimately, by performing Energy Efficiency Assessments on a number of data center environments (both large and small as the savings scale) to create a baseline and then implementing the recommendations and re-measuring energy usage, IT load reductions is best area of focus. This has the dual benefit of reducing energy consumption on the primary IT load as well as realizing energy savings on facility support infrastructure as a result of lower cooling energy usage required to cool the IT load.

Strategies that Work

We recommend several specific strategies when considering improvements or new design elements in achieving energy-efficient IT operations. These strategies include:

  • IT Systems Re-design. There are a number of IT re-design options to reduce power consumption. Currently, the number one approach is to leverage virtualization across server and storage infrastructure.

  • Scalable Deployments. More closely match power and cooling capacity to the actual load. The power penalty of "fixed losses" from under-loaded equipment can be significant.

  • Close-Coupled Cooling with Air Balancing and Partial Containment. Air mixing is the enemy of effective cooling. In-row or close-coupled cooling solutions greatly reduce air mixing by closely coupling the IT equipment's hot air discharge with the CRAC/CRAH's hot air return and the CRAC/CRAH's cold air supply with the IT equipment's inlet. Additionally, close-coupled CRAC/CRAH units have the capability of varying their airflow, thereby balancing their supply CFM commensurate with the CFM requirements of the IT equipment using either temperature and/or pressure as a control. Air mixing can further be reduced by implementing partial hot-aisle containment by deploying air containment curtains and/or doors at the ends of each "hot" aisle.

  • Raise the Data Center Temperature with Chilled Water Cooling. ASHRAE has issued a modified recommended thermal envelop for server inlet temperature and humidity. Its recommendation for acceptable room temperature raising the average temperature in the data center from 68 F/20 C to 80.6 F/27 C and provides acceptable conditions for IT infrastructure, particularly servers, to function at acceptable levels of performance.

Industry Perspectives is a content channel at Data Center Knowledge highlighting thought leadership in the data center arena. See our guidelines and submission process for information on participating. View previously published Industry Perspectives in our Knowledge Library.

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