Thermal and Airflow Management

The energy and operational demands on data centers are increasing at an alarming pace. Convergence of voice, video and data, the rapid growth in social networking and the overall growth in demand for data services are pushing the limits of many existing data centers. Add to that the increasing cost of electricity, the pressure on cost containment and the constantly changing technology, and you can appreciate the challenges facing data center operators, managers and facility managers. With up to 50% of electrical energy consumption being used for data center cooling, finding ways to reduce the heat in a data center can add up in energy cost savings quickly.

Cooling Management

Older data center configurations typically have cabinets lined up such that the hot air coming out of the back of the cabinet meets with the cold air coming into the front of the next row of cabinets. As the density of servers within cabinets increases, along with heat production, this configuration becomes very inefficient. Redesigned or newer data centers typically use hot aisle/cold aisle configurations – cabinet fronts face each other in an aisle (cool air intake) while cabinet backs face each other in an aisle (hot air exhaust). Various hot aisle/ cold aisle configurations can be designed based on various parameters such as data center size and dimensions, raised versus hard flooring, ceiling clearances and cooling objectives. High-level approaches include:

• Perimeter cooling with CRAC units using combinations of ducted and non-ducted solutions for both supply of cold air and return of hot air.
• In-rack and in-row cooling focuses on cooling specific rows or racks which leads to better predictability, higher density support and higher efficiency.
• Passive cooling that pulls hot air out of the cabinet through a specialized chimney system and directs it out of the data center building. Outside air, depending on the climate, can be directed into the data center for cooling.

Designing your data center to optimize your cooling, minimize your expense and maximize your future flexibility requires the knowledge to understand the various design options available and the technology and systems available to support those designs. Graybar's technical specialists have the knowledge and ability to assist you in meeting your cooling objectives.

Airflow Management

A 2006 study performed by the Uptime Institute, Inc., found that up to 72% of the available supply of cold air was bypassing the computer equipment it was meant to cool. A large percentage of this was attributed to cold air leakage. Use of grommets, boots and plugs enable maximum sealing effectiveness and better cooling efficiency. Well-designed cable management systems will also improve airflow management by reducing cable congestion and ensuring cables are not obstructing cool or hot airflow in the floor, ceiling or within the cabinets. Airflow within cabinets can be improved through the use of blanking plates to block off unused portions of the cabinet or to block off the front of cabinets to prevent cooling of unused sections or to prevent hot air recirculation. Taking the time to review your airflow management will pay back in the short term by uncovering the high percentage of air bypassing that may be happening in your facility!

Fluid Cooling Control

Most chillers operate 99% of the time at less than full load. Variable-frequency drives (VFD) can be used to match the system output to the load requirements by slowing down the motor. This results in significant energy savings with a payback usually between 6-36 months (FacilitiesNet.com, March 2009). The softer start provided by VFDs puts less stress on the compressor motor and other electrical components which can positively affect equipment reliability and longer life.