Ashrae Journal - November 2008 - (Page 16)

5 a.m. to 11 a.m. and then begins to drop again at 5 p.m. Server power consumption remains relatively high as server load decreases. In idle mode, most servers consume between 70% and 85% of full operational power. Consequently, a facility operating at just 20% capacity may use 80% of the energy as the same facility operating at 100% capacity. Server processors have power management features built-in that can reduce power when the processor is idle. Too often these features are disabled because of concerns regarding response time. However, this decision may need reevalu- www.info.hotims.com/16019-21 ation in light of the significant savings this technology can enable. In the data center model, it is assumed that idle power draw is 80% of the peak power draw without power management, and reduces to 45% of peak power draw as power management is enabled. With this scenario, power management can save an additional 86 kW or 8% of the unoptimized data center load. 4. Blade servers. Many organizations have implemented blade servers to meet processing requirements and improve server management. While the move to blade servers is typically not driven by energy considerations, they can play a role in energy consumption. Blade servers consume about 10% less power than equivalent rack mount servers because multiple servers share common power supplies, cooling fans, and other components. In the data center model, there is a 1% reduction in total energy consumption when 20% of rack-based servers are replaced with blade servers. More importantly, blades facilitate the move to a high-density data center architecture, which can significantly reduce energy consumption. (See Strategy 9 on High Density Supplemental Cooling.) 5. S erver v irtualization. As server technologies are optimized, virtualization is increasingly being deployed to increase server utilization and reduce the number of servers required. In the data center model, it is assumed that 25% of servers are virtualized with eight nonvirtualized physical servers being replaced by one virtualized physical server. We also assume that the applications being virtualized were residing in single-processor and two-processor servers and the virtualized applications are hosted on servers with at least two processors. Implementing virtualization provides an incremental 8% reduction in total data center power draw for the 5,000 ft2 (465 m2) facility used as the data center model. 6. Cooling best practices. Most data centers have implemented some best practices, such as the hot-aisle/cold-aisle rack arrangement. Potential exists in sealNovember 2008 16 ASHRAE Journal http://www.est-aegis.com/aj2 http://www.est-aegis.com/aj2 http://www.info.hotims.com/16019-21

Table of Contents Feed for the Digital Edition of Ashrae Journal - November 2008

Ashrae Journal - November 2008 Contents Commentary Industry News Meetings and Shows Feature Articles Reducing Data Center Energy Consumption Building Sciences Feature Articles Sustainable Nature Center Emerging Technologies Special Products Washington Report Special Supplement: BACnet® Today BACnet® Goes Green Seeing the Light with BACnet® BACnet® on Campus BACnet® for Net Zero Analyzing BACnet® BACnet® at Xerox Campus BACnet® in Europe BACnet® for Green Library BACnet® at the University of Minnesota: Flexibility, Interoperability InfoCenter Product Showplace Classified Advertising Advertising Index

Ashrae Journal - November 2008

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