Cooling a More Mature Green Data Center


The concept of "going green" in the data center may have jumped the shark, as the saying goes, but only in the sense that adopting energy-efficient technologies and practices is no longer about catch phrases and empty promises.

Instead, it appears that the movement is transcending the novelty phase and has settled in as a permanent component of the upgrade and expansion process. That means you're less likely to see green technologies put in place for their PR factor as much as for their impact on the bottom line.

Nowhere is this more apparent than in cooling systems. Where once the standard practice was to build out massive cooling structures regardless of their consumption, the newest designs are all about keeping systems cool without busting the budget.

For example, Google recently powered up a chillerless data center in Belgium, foregoing the massive refrigerators that typically inhabit large facilities in favor of naturally cool water from a nearby industrial canal. On the few days of the year when it gets too hot, the company plans to shut down systems and shift loads to other centers.

Air-cooling systems are also getting a makeover. APC just launched a series of row-based cooling systems that not only use less power than traditional designs, but are more scalable and can be installed in greater densities. The system focuses cool air directly onto rows of servers, allowing particular rows to receive additional cooling if they are running high-density applications. A single 600 mm row provides up to 7 kW of cooling capacity and comes equipped with monitoring and automation features to dynamically adjust capacity to maintain constant temperatures at the server inlets.

Another movement afoot in energy-efficient circles is coordination with power and cooling experts at the systems integration stage. Sun Microsystems recently teamed up with Emerson Network Power to offer customized solutions for individual facilities. Emerson maintains power and cooling specialist teams throughout the world capable of devising plans and initiating specific products and services designed to improve data center efficiency. One of their first customers is Sandia National Laboratories, which recently received a new series of Sun Blade X6257 modules and the Sun Cooling Door system tied to Emerson's Liebert XD cooling platform.

When it comes to keeping things cool, the twin dangers are doing too little and doing too much, according to Amazon engineer James Hamilton. On the too little side, he lists failing to seal air flowing into and out of the rack, while the too-much crowd includes enterprises that tend to over-cool their rooms. The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) recommends 81 degrees F for today's servers, with an allowable range that extends to 90 degrees. If you look hard enough, you might even find some equipment that's rated for over 100 degrees.

Despite the advances that have taken place in cooling systems of late, the fact is that energy efficiency remains the second most important factor in any redesign. The primary consideration should be reliability. All the energy savings in the world won't amount to a hill of beans if the system fails outright or fails to maintain a proper working temperature.

The good news is that these two requirements are not at odds anymore. Greater efficiency is working hand-in-hand with greater reliability, which means you still maintain the same productivity you had before -- you just pay less for it over time.