By Eric Leichter, Senior Manager for CommScope Enterprise Global Services | Jul 9, 2009

The topic of the day seems to be “Green”, which includes the entire spectrum of using less energy and materials at the start, being more efficient during a building’s life cycle, and extending that life cycle to reduce the replacement of components and their associated waste. The growth of data centers in the United States and globally has led companies to look hard to increase efficiency and productivity of the resources utilized in the storage, transport, and processing of data. Focusing on the cabling infrastructure system in this article, we will examine some of the issues surrounding energy usage and how to reduce waste. And, especially important in today’s environment, we will look at the other green as well – yes, dollar$ -- and see how being green can save some green.

Data centers are basically big computer rooms that use optimized infrastructure components to support servers, storage, and networking equipment devices. The dramatic increase in internet usage driven by Web 2.0 companies (video downloads and uploads from Youtube, file and image sharing sites like Shutterfly, social websites like Facebook, etc) and the resultant demand for bandwidth has led to an equally dramatic increase in the number, size, and density of data centers. And they are having trouble keeping pace.  63% of IT decision-makers report that their data center had run out of space, power or cooling without notice. 43% reported that at their current rate of growth – they could only stay in their current infrastructure for 6 months with no changes. Not surprisingly, 36% are currently planning or building new data centers (OnStor, AFCOM, ARI, Dec 07)

Data centers have already grown to consume about 2% of the total US electrical usage and are forecast to consume a whopping 9% of the US total by the year 2020. Much of this power is required to run the electronics and building operations. These electronics generate a lot of heat, which is one of the major causes of electronic failure within the data center. IT hardware reliability is greatly reduced as temperatures rise. It is estimated that a 10°C increase in temperature reduces the long-term reliability of the electronics by 50% (Arrhenius Theory).

Ironically, the electronics that are the heart of a data center’s operations are creating the very heat that will reduce their effectiveness and lifetime, at the rate of 1W of cooling required for every watt or power consumed by electronics.

More frequent replacement of these components leads to more waste in landfills and higher costs of operation. As higher density electronics such as blade servers are becoming prevalent, the cost of a typical server is becoming outweighed by the cost of running the cooling to support it.

To control the flow of air, many data centers have adopted a pattern of cold aisles for the electronics and hot aisles for underfloor cable routing and passive patching. Cold air can be added and hot air removed in a very controlled pattern, leading to better efficiencies from the cooling equipment. Notably, passive cabling, both UTP and optical fiber, is less affected by heat than the active equipment.

Energy wasted on cooling equals wasted resources and dollars. Large data centers provide up to 270% of the cooling needed by the equipment due to inefficient airflow management. In order to reduce this waste, follow some of the golden rules of thermal management:

• Use blanking panels to stop recirculation of the hot air
• Use vented doors with at least 60% open area
• Distribute blade servers evenly to prevent “hot spots” in your data center
• Size the air conditioning appropriately for size of the computer room.  on a typical average
• Turning down the air conditioning temperature will not solve a heating/cooling problem
• Modularize the thermal solution to limit initial investment
• Utilize a structured cabling system to limit the blockage of airflow
• Proper raised floor cable design and management;
• High voltage cables on floor of cold aisles
• Low-voltage communications cabling under cabinets or directly under floor tile in hot aisle.
• Reduce the number of perforated floor tiles in the design, only placing perforated tiles in front of active cabinets.