Cooling Upgrade Increases Efficiency
EP Editorial Staff | January 13, 2017
Variable-speed technology and intelligent controls combine to reduce data-center operating expense.
There are several reasons to consider upgrading your data center’s thermal-management system, including improving capacity management, deferring capital costs, and promoting environmental responsibility. You may simply want to improve energy efficiency and reduce operating costs. In a typical data center, cooling accounts for approximately 38% of total energy consumption.
Regardless of your specific goal, if thermal-system upgrades are on your mind, you are not alone. A recent survey of information technology (IT), facilities, and data center managers in the United States and Canada found that 40% of data centers have been upgraded in the past five years. Twenty percent are in the process of upgrading, and more than 30% would be upgraded in the next 12 months.
Why the surge in thermal-upgrade projects? There is continuous pursuit for higher equipment reliability, greater energy efficiency, additional capacity, and greater insight into performance. What can’t be overlooked is the fast return on investment (ROI) achieved by those who have recently upgraded. One such company is QTS Realty Trust Inc., headquartered in Overland Park, KS. The company owns, operates, or manages 24 data centers and supports more than 1,000 customers with its data-center solutions.
QTS has experienced significant growth over the past 10 years, going from owning a single data center in 2005 to a coast-to-coast portfolio of 12 centers encompassing more than 4.7 million sq. ft. To ensure continued provision of leading-edge services and optimal performance from its newly acquired Sacramento, CA, facility, the company required improved cooling-system efficiency and greater visibility into system performance. An upgrade of fans and controls, using the latest in cooling technology, was warranted to maintain cooling stability, improve efficiency, and reduce costs.
The aim was to generate enough cost savings to yield a full ROI in 2 1/2 yr. At the same time, the company also wanted advanced monitoring capabilities to continue best-practice data-center management.
The need for improved system visibility that would allow QTS to provide its customers with more uniform cooling, coupled with the desire for cost savings generated from improved energy efficiency, led the company to upgrade the Sacramento facility. Experiencing a very common energy-efficiency challenge in its data center, employees found that the legacy cooling systems were providing more airflow than was required in one area, while another had a deficit. Installing electrically commutated (EC) fan technology from Emerson Network Power, which is now known as Vertiv (Columbus, OH, vertivco.com) into 64 cooling units would allow cooling adjustments based on load requirements.
Management sought to partner with a company that could complete the project within a fixed five-week timeline with limited use of QTS resources and manpower. Another key challenge was that only a certain number of units could be off at any one time to maintain the level of redundancy required. This stipulation called for careful planning and coordination to ensure the project could be completed within the parameters specified. QTS also wanted to ensure their upgrade was performed by a service provider that had experience configuring the latest technology for business-critical data centers. As the original equipment manufacturer (OEM), Emerson Network Power’s Liebert Services, now part of Vertiv, was chosen to ensure high-quality parts and installation from factory-trained technicians.
Originally electing to only install EC plug fans, QTS management quickly realized it was missing the opportunity to optimize the cooling system for maximum efficiency benefits. Company leaders determined it could better achieve its stability and visibility goals through the addition of the Liebert iCOM control system, which enabled under-floor pressure control through building-management-system (BMS) integration. Wireless sensors were also installed to monitor cooling improvements.
This more holistic approach gave the company added flexibility through multiple configurations inherent to the controls that balance loading in the space. These configurations include control by wireless and remote temperature sensors, advanced supervisory control, or BMS control. QTS now has the option to coordinate fans, perform auto-tuning, and customize staging or sequencing whenever it is needed to further improve energy efficiency, availability, and flexibility.
The entire thermal-system upgrade project, performed within an operating data center, was completed on time without any negative impact on the company or its customers. As a result of the upgrade, QTS earned a $150,000 rebate from the Sacramento Municipal Utility District and initially saved $12,000 a month in energy costs. Additional savings are expected from continued optimization.
In addition to the obvious financial benefits, QTS accomplished the following with its thermal-system upgrade:
• Reduced its carbon footprint with more than 75% immediate reduction in the energy consumption using Liebert thermal-management units
• Improved Power Usage Effectiveness (PUE) by 0.16
• Provided better intelligence to BMS for improved visibility
• Improved uniformity of under-floor static pressure, allowing adjustment of air flow to match equipment loads by changing floor tiles
• Eliminated air leakage through cooling units that were previously off or in standby using the control’s proprietary virtual damper
• Exceeded minimum ROI estimates by 40% and achieved targeted savings sooner than budgeted
• Maximized free cooling through improved unit airflow and cooling control.
According to QTS western region vice president Ken Elkington, the results of the upgrade far exceeded his expectations. “We took amp draw measurements on the existing fans. As soon as we placed the first new EC plug fan into a unit, even at 100 percent speed, the power consumption dropped 30 percent,” he said. “We were very excited to see that result, but then it got even better. By varying the fan speed to match the load in the zone, the power consumption dropped another 33 percent, and we are now experiencing higher-than-expected energy savings.” MT
For more information, visit vertivco.com.