Amazon data center facility engineer touts radical cooling tactics

Amazon Web Services data center facility guru James Hamilton says data center pros need to get out of the dark ages when it comes to cooling servers. Hamilton recommends airflow containment systems and air-side economizers to improve data center cooling efficiency.

Many IT departments may be wasting valuable resources by using outdated approaches to data center cooling, said...

James Hamilton, VP and Distinguished Engineer at Amazon Web Services, in a talk he gave at the recent Usenix Conference in San Diego.

Hamilton said the first step is to provide tighter control of airflow in the data center. He suggests connecting server racks to a container system that seals air flow into and out of the rack, providing better control over air temperature. When attached to a sealed enclosure, little air is lost -- or mixed. Variable speed fans inside the container as well as tight feedback between computer room air conditioner (CRAC) and the heat load will enable a system to eliminate inefficiencies in the server fans. (Read more on data center cooling containment systems.)

Hamilton also noted that many data centers waste energy by keeping servers cooler than necessary. According to the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), the recommended inlet air temperature for servers is 81 degrees Fahrenheit. The ASHRAE specification sets an allowable temperature of 90 degrees. Hamilton noted that some Dell servers are warranted for 95 degrees, while telco equipment and some servers can run at 104 degrees.

While these approaches can save energy, there are some risks to raising inlet air temperatures.

Because many systems can run at higher temperatures without problems, Hamilton suggested using outside air to cool computing equipment, with air conditioning available as needed. This cooling strategy is called an air-side economizer.

He noted that there may be issues with particulates, especially if a generator is being run near the air input or there is a fire nearby. To reduce these issues, he notes that filtration and other techniques can prepare the air to be pumped through the data center. (Read more about data center air-side and water-side economizers.)

For more information about Hamilton's take on data center efficiency and other issues, check out his blog. You can download Hamilton's data center energy efficiency presentation here.

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