Documenting an Economization Project

I got a chuckle at an event earlier this year when Sun Microsystems’ Subodh Bapat referred to air-side economization as “a fancy term for opening the windows in the data center.” It may be a basic concept, but some data center operators are finding significant gains by putting it into practice.

One example is the Red Rocks Data Center in Morrison, Colorado, which recently installed an air economizer system to cool a colocation room with 24 cabinets. The company launched a blog to document the project, complete with a photo gallery and a status page that provides a real-time indicator of whether the economizer system is in use, along with data about the company’s energy savings. Early data suggest Red Rocks can save more than 75 percent on energy costs when the economizer is in use.   

Climate is a key factor in whether air-side economization will be effective, since it can only be used at temperatures of 72 degrees or lower. The team at Red Rocks Data Center believes they’ll get plenty of use out of its economizer system, and is giving it a prominent role in its green marketing story.

Heat Wheel Could Cut Data Center Cooling Bills

A relatively new approach to data center cooling known as a “heat wheel” is gaining momentum, and likely to gain a higher profile from an upcoming demonstration of the technology. The heat wheel - also known as a rotary heat exchanger or Kyoto Cooling - is a refinement of existing approaches that take advantage of outside air to improve cooling efficiency and reduce data center power bills. 

Proponents of the heat wheel say it improves upon air-side economization (free cooling), the use of outside air to cool servers in the data center. Rather than introducing exterior air directly into the server room, the heat wheel briefly mixes the outside air and exhaust air to creates an “air-to-air” heat exchanger. 

“The inside heat from the IT room is still removed via the heat wheel, but there is minimal air transfer between the ambient and the computer room,” explains Uptime Technology BV of the Netherlands. “This system has all the benefits of Airside Economizing, without the exposures of airside economizing like contamination and humidity control.”

Did Google, Intel Discuss Hotter Chip Specs?

Google’s practices on data center temperature have prompted discussions with Intel, according to The Register, which says Google has asked Intel to certify its chips to operate at temperatures five degrees warmer than its standard specs. Intel denies that it has extended any special guarantees to Google, which buys chips and motherboards directly from Intel for its custom web servers.

The story cites a former Google employee, who also says that using data center containers is ”now the norm” for Google. We reported last week that Google’s patented containers may be among the innovations helping it achieve exceptional energy efficiency ratings.

Google says it can operate its data centers at 80 degrees, and is among a growing number of companies advocating higher cooling set points as a strategy to save on data center power costs.

The Register story is also being discussed at Slashdot.

Google: Raise Your Data Center Temperature

The biggest players in the data center industry are raising the thermostats in their data centers, with some saving hundreds of thousands of dollars in energy costs in the process.

The latest company to focus attention on temperature in the data center is Google. “The guidance we give to data center operators is to raise the thermostat,” said Erik Teetzel, an Energy Program Manager at Google. “Many data centers operate at 70 degrees or below. We’d recommend looking at going to 80 degrees.”

Most data centers operate in a temperature range between 68 and 72 degrees, and some are as cold as 55 degrees. Raising the baseline temperature inside the data center - known as a set point - can save money spent on air conditioning. Data center managers can save 4 percent in energy costs for every degree of upward change in the set point, according to Mark Monroe of Sun Microsystems, who discussed data center set points at a conference last year. But nudging the thermostat higher may also leave less time to recover from a cooling failure, and is only appropriate for companies with a strong understanding of the cooling conditions in their facility. 

“The first thing you should do is make sure you know what your airflow looks like,” said Google’s Teetzel. Air flow analysis using computational fluid dynamics (CFD) and placing temperature sensors on server inlets are strategies that can give data center managers a detailed picture of thermal conditions in their facility.

Raising the set point is a key goal of Hewlett Packard’s Dynamic Smart Cooling product, which incorporates CFD, a sensor network, and a central server to monitor and adjust cooling. A similar approach is offered by DegreeC’s AdaptivCool solution.

How much money can you save by raising the cooling set point in the data center? Microsoft (MSFT) wanted to find out, and tested the impact of slightly higher temperatures in its Silicon Valley data center. “We raised the floor temperature two to four degrees, and saved $250,000 in annual energy costs,” said Don Denning, Critical Facilities Manager at Lee Technologies, which worked with Microsoft on the project.

CFD Thermal Modeling: Who’s Using It, and How?

One of the cool technologies in use in some data centers is thermal modeling using Computational Fluid Dynamics (CFD),  a tool for analyzing the effectiveness of cooling within the racks and aisles. The 3D visualizations of a data center are visually striking, but can also save data center operators large sums of money by identifying areas where cold air is not reaching equipment or is mixing with hot air. 

Since cooling can represent 40 percent of energy usage in some data centers, the savings from a CFD analysis can be significant. But so can the up-front cost, which is a challenge in technology adoption.

Customers of CFD modeling fall into three primary categories, according to Sherman Ikemoto, General Manager, North America for Future Facilities,  a UK-based company that specializes in CFD tools:

• Hardware manufacturers such as Dell, IBM, Verari Systems and Cisco, who use Future Facilities’ 6Sigma software to understand the thermal profile of their equipment.
• Building services firms such as EYP Mission Critical Facilities (now part of HP) and BrunsPak, who use CFD modeling to perfect air flow in their data center designs before starting construction.
• Data center operators who use 6Sigma and other CFD to trouble-shoot existing facilities to track airflow changes as more racks and cabinets are added to a data center.

Among companies operating data centers, use of CFD is concentrated in banks and brokerages. “We are mainly strong in the financial sector,” said Ikemoto. “They seem to have the top mission-critical facilities, and they’re constantly upgrading their facilities. They see their data center as a necessity, not as overhead.”  

Intel: Servers Do Fine With Outside Air

Do servers really need a cool, sterile environment to be reliable? New research from Intel suggests that in favorable climates, servers may perform well with almost no management of the environment, creating huge savings in power and cooling with negligible equipment failure.

Intel’s findings are detailed in a new white paper reviewing a proof-of-concept using outside air to cool servers in the data center - a technique known as air-side economization. Intel conducted a 10-month test to evaluate the impact of using only outside air to cool a high-density data center, even as temperatures ranged between 64 and 92 degrees and the servers were covered with dust.

Intel’s result: “We observed no consistent increase in server failure rates as a result of the greater variation in temperature and humidity, and the decrease in air quality,” Intel’s Don Atwood and John Miner write in their white paper. “This suggests that existing assumptions about the need to closely regulate these factors bear further scrutiny.”

Intel set up a proof-of-concept using 900 production servers in a 1,000 square foot trailer in New Mexico, which it divided into two equal sections using low-cost direct-expansion (DX) air conditioning equipment. Recirculated air was used to cool servers in one half of the facility, while the other used air-side economization, expelling all hot waste air outside the data center, and drawing in exterior air to cool the servers. It ran the experiment over a 10-month period, from October 2007 to August 2008.

The temperature of the outside air ranged between 64 and 92 degrees, and Intel made no attempt to control humidity, and applied only minimal filtering for particulates, using “a standard household air filter that removed only large particles from the incoming air but permitted fine dust to pass through.” As a result, humidity in the data center ranged from 4 percent to more than 90 percent, and the servers became covered with a fine layer of dust.

A Third of Data Centers in the Dark on Power

Thirty six percent of data center managers say they don’t know whether their electric bills increased between 2007 and 2008, suggesting that a large chunk of the industry continues to operate their facilities without effective communication aboutpower costs. That’s one of the findings from a survey of 600 facilities managers by Data Center Decisions, which is summarized at Tech Target.

The survey shows strong adoption of energy effiency strategies, including server virtualization, improving air conditioning efficiency, and powering down idle servers. The numbers suggest that many data center operators are implementing  technologies to lower their power bill, yet may not know how much they are saving.

Green Grid, ASHRAE to Collaborate

The Green Grid and ASHRAE will work together on publications that provide guidance on data center design, a development that could improve the effectiveness of data center cooling. The two groups said today that they will share technical information on energy efficiency.

ASHRAE develops best practices for 50,000 professionals in HVAC (heating, ventilation and air conditioning), and has issued recommendations for data center efficiency through its Technical Committee 9.9. The Green Grid is an industry consortium of data center operators and vendors.

‘Roll Your Own’ Thermal Monitoring

Blade servers and high-density racks continue to create “hot spots” inside data centers. Detecting these hot spots before they cause servers to overheat is a critical challenge. There are a growing number of vendor offerings that can provide data center managers with sophisticated thermal mapping and monitoring of their facilities. But in recent weeks we’ve seen several providers develop their own monitoring systems. Here’s a look at two innovative approaches to hot spot detection:

• Austin colocation provider Core NAP has built a system of low voltage thermal sensors tied together over Cat5 cable, which is summarized at IT Knowledge Exchange: “The monitors report back to a database that can map data center temperatures in real-time. (Core NAP) plans to be able to put multiple monitors in cabinets, under floors, and in the cable runs above of the racks. The sensors from Maxim IC report to USB readers plugged into Linux hosts. The hosts log data to a local web server, and Core NAP plans to combine that info with Visio maps of the data center.” Jeremy Porter, the Senior Internet Data Center Architect at Core NAP, says this approach will save money compared to off-the-shelf solutions.

IBM Cool Blue Shines in Vendor ‘Chill Off’

IBM’s Cool Blue Rear Door Heat eXchanger liquid cooling unit earned bragging rights in a head-to-head vendor “chill off” that tested the energy efficiency of vendor cooling products in the same data center environment. The unusual competition between leading cooling technologies from IBM, APC, Emerson Network Power and Rittal Corp. was sponsored by the Silicon Valley Leadership Group (SVLG), which announced the results yesterday during the group’s Data Center Energy Summit in Santa Clara, Calif.

Cool Blue, developed by IBM and licensed by Vette Corp., is a rear door heat exchanger that doesn’t use fans, which gave it an energy advantage over competing products in the analysis, according to Dean Nelson, Senior Director of Datacenter Design Services at Sun Microsystems, who presented the findings. There was also keen interest in the results for APC and Emerson Network Power’s Liebert unit, which wound up virtually deadlocked, with APC products faring slightly better at low power loads while Liebert’s gear was more efficient as loads neared 10 kilowatts per rack, the upper limit for the testbed.

Rittal’s LCP rack-based liquid cooling product trailed the pack. The full results and testing criteria for the chill-off are available on the Accenture web site (PDF) along with all of the 11 case studies presented during the SVLG energy summit.

The unusual contest was conducted in Sun Microsystems’ data center in Santa Clara, with officials from Lawrence Berkeley National Labs overseeing the testing, and Modius providing the metrics with its OpenData Data Center Infrastructure Manager software. More than 40 million individual measurements were taken during the study.