Electronics Protection - September/October 2012 - (Page 18)

Feature Maximizing Availability, Capacity and Efficiency with Rising Data Center Temperatures higher return air temperatures. A 10°F increase in return air temperature typically results in a 30 to 38 percent increase in cooling unit capacity and a 15 to 20 percent increase in system efficiency. Data center best practices have advocated a narrow temperaIn order to operate the IT equipment reliably at warmer temture-operating band for years. Recently, however, it has been shown peratures, some form of containment should be considered. Cold that they can safely operate at both higher and lower temperatures. aisle containment is favored over hot aisle containment because it What does this mean for data center managers? Adopting data cen- is simpler to deploy and reduces risk during the event of a breach ter cooling best practices ensures using a wider temperature band of the containment system. With hot aisle containment, open doesn’t result in downtime or efficiency trade-offs. doors or missing blanking panels allow hot air to enter the cold Data center complexity has aisle, jeopardizing the perincreased as they experienced formance of IT equipment. growth in capacity and denIn a similar scenario with the sity, straining resources and cold aisle contained, cold increasing the consequences air leaking into the hot aisle of poor performance. The decreases the temperature challenge running a data cenof the return air, slightly ter warmer is managing aircompromising efficiency, but flow. The ASHRAE suggested not threatening IT reliability. temperature band of 64°F to Row-based cooling units 80°F for requires the separacan operate within the tion of cold air that enters the contained environment to servers versus the hot air that supplement or replace peleaves. If the two airstreams rimeter cooling. This brings Figure 1. In the hot-aisle/cold-aisle arrangement, racks are placed in rows facemix the result is reduced eftemperature and humidity ficiency for the cooling system to-face, with a 48-inch aisle between them. Cold air is distributed in the aisle and control closer to the source used by racks on both sides. Hot air is expelled to the rear into the hot aisle. and/or failure of servers due of heat, allowing more to the hot temperatures. precise control and reducing Below are best practices data center managers can perform on the the energy required to move air across the room. By placing the cooling side to increase efficiency, availability and capacity. return air intakes of the cooling units directly in the hot aisle, air is 1. Organize Racks in a Hot/Cold Aisle Arrangement captured at its highest temperature and cooling efficiency is maxiA hot-aisle/ cold-aisle rack arrangement (Figure 1), can mitigate mized. The downside of this approach is that more floor space is air mixing as it returns to the cooling unit. This is the first step of used in the aisle. Row-based cooling can be used in conjunction airflow management. Whether your application is raised floor or with traditional perimeter-based cooling in higher density zones non-raised floor, the racks must be arranged this way. throughout the data center. 2. Install Blanking Panels in and Between Racks 7. Match Cooling Capacity and Airflow with IT Loads Blanking panels prevent the hot air from circulating to the front The most efficient cooling system is one that matches needs to of the rack where the electronic equipment air intakes are located. requirements. This has proven to be a challenge in the data center 3. Place CRAC Units Correctly in the Room because cooling units are sized for peak demand, which rarely ocCRACs should be located at the end of hot aisles to reduce air curs in most applications. This challenge is addressed through the travel and prevent hot air from being pulled down into cold aisles use of cooling controls capable of understanding, predicting and as it returns to the air conditioner. If the cooling units cannot be adjusting cooling capacity and airflow based on conditions within positioned as so, a drop ceiling can be used as a plenum to prevent the data center, paired with variable capacity fans and compreshot air from mixing with cold air as it returns to the cooling unit. sors. Intelligent controls enable a shift from cooling control based Cooling units can also be placed in a gallery or mechanical room. on return air temperature, to control based on server conditions, 4. Seal the Raised Floor and Minimize Cables and Pipes which is essential to optimizing efficiency. This often allows temIn raised floor applications make sure that there are no leaks peratures in the cold aisle to be raised closer to the safe operating at cable penetrations, perimeter penetrations and raised floor threshold now recommended by ASHRAE (max 80.5°F). tile joints. If cables have to be in the raised floor or cannot be The control system also contributes to efficiency by allowing removed, they should be under the hot aisle running parallel with multiple cooling units to work together. The control system can the aisle. You can also use a cable management system in the shift workload to units operating at peak efficiency while preventracks so cables do not obstruct the exhaust air from servers. ing units in other locations from working at cross-purposes. With5. Optimize Perforated Tile Locations out this type of system, a unit in one area may add humidity to the Conducting a thermal assessment of the data center using room at the same time another unit is extracting it from another. computational fluid dynamics (CFD) is a good way to optimize the Working with data center design and service professionals location of perforated tiles in raised floor applications to implement these best practices, and modify them based on 6. Maximize Cooling Units Return Temperature to Improve changes the data center, creates the foundation for a data center Capacity and Efficiency in which availability, efficiency and capacity can all be optimized. This best practice is based on running warmer temperatures in the space, which improves cooling unit performance by creating For more information visit www.emersonnetworkpower.com. 18 September/October 2012 www.ElectronicsProtectionMagazine.com Dave Kelley, Director, Liebert Precision Cooling Engineering Emerson Network Power http://www.emersonnetworkpower.com http://www.ElectronicsProtectionMagazine.com

Table of Contents for the Digital Edition of Electronics Protection - September/October 2012

Electronics Protection - September/October 2012
Table of Contents
HP Intelligent Series Racks Offer Monitoring Capabilities for Data Centers
The Unknown Problem with Airtight Enclosures
Key Drivers When Turning to Captive Panel Screws
Emerging Trends in Field Equipment Enclosures
JV Industrial Solves Power Outage Issues with Battery-Free Flywheel
The Green Data Center Opportunity
The Power-Grid and Protecting Electronic Devices
Maximizing Availability, Capacity and Efficiency with Rising Data Center Temperatures
Canyonwest Cases Releases new Enclosures for Flat-Screen TV Transportation
Ohmite Manufacturing Releases Radial-Fin Heat Sink Extrusions
Rogers Introduces Condux Plus Conductive Foams
FIP Gasketing Resin Offers Advantages over Gasketing Materials
Minmax Power Releases MSGWI06 Series of DC/DC Power Modules
New E-Line Locking Systems Reduce Security Costs and Enhance Locking Solutions
Industry News
Calendar of Events

Electronics Protection - September/October 2012