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Home > Facilities > Data Centers > Demonstrations

Demonstration Projects - Datacenters

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(LBNL also participated in the SVLG Case Study Project)

Use of DC power

DC powered servers

LBNL is continuing to work with many firms that participated in a demonstration of DC power which demonstrated that energy savings are possible by eliminating multiple conversions of alternating and direct current that typically occurs in today's data centers. The objectives of this demonstration were to show that DC powered servers could readily be built from existing components and reliably provide the same level of functionality as their AC powered counterparts. Energy efficiency gains were expected by eliminating the power losses that occur during power conversion. A traditional AC distribution system was set-up along side of the new DC distribution system at a Sun Microsystems facility using components loaned by industry partners (including DC lighting). Intel and Sun Microsystems modified servers to directly accept high voltage (380V) DC power. Both systems were fully instrumented in order to measure electrical power losses at various points in the system and preliminary results are indicating energy savings of 10-15% within the electrical distribution system. This saving is compounded with additional saving through reductions in the cooling that is required — typically about the same amount — so the result is an overall facility level saving. Estimates of data center energy use nationally have been placed at 10-15 TWh so implementing this strategy could be significant. Large numbers of data center professionals are viewing the demonstration in open house tours and have expressed interest in seeing the technology adopted. [more information]

"Air Management" Improvement

Illustration showing the flow of air between hot and cold aisles.

IT equipment housed in data centers today rely on air cooling. In most cases, air distribution in the centers involves mixing of cooled air with air that has been heated by the IT equipment making it difficult to supply the cool air to where it is needed and resulting in inefficient heat transfer to the cooling system. LBNL demonstrated that large energy savings are possible by completely isolating the cold and hot airstreams. The objective of the study was to demonstrate feasibility and quantify savings when certain isolation strategies were implemented. The test configurations were implemented in LBNL's Oakland Scientific Facility housing the National Energy Research Scientific Computing (NERSC) supercomputers. In one arrangement where "cold aisles" were completely isolated using temporary partitions, six fold energy savings in fan energy were measured. In another, where the "hot aisle" was isolated, three fold fan energy savings were observed. In both schemes, additional efficiency gains of the chilled water system were calculated based upon the ability to raise the temperature of the cold air supply since undesired mixing of hot and cold air streams was eliminated. This demonstration is important because it shows the resulting energy savings along with other non-energy benefits of more uniform cooling which has reliability implications.

Encouraging Use of Outside Air Economizers in Data Centers

Graph illustrating indoor particle concentration; x-axis = time in 12 hour increments; y-axis = particle concentration (ug/m3);

In many parts of the country, there are many hours per year where the outside air conditions are such that IT equipment could be cooled by directly supplying outside air thereby minimizing or eliminating the use of chillers. There are a number of data centers that routinely use outside air economizers but there also are a large number of centers where there is a belief that bringing in large amounts of outside air will cause problems. Common concerns are that contamination levels would increase and cause failures of IT equipment or that humidity control would be a problem. LBNL is addressing this by measuring contamination levels in both centers that use outside air and those that don't. Particle counters are used to measure concentrations of various size particles inside and outside of the centers. Simultaneously, humidity is being measured to see if there are issues concerning humidity control. The primary objective of this demonstration is to obtain some evidence that use of outside air is either not a concern, or to develop recommendations to mitigate any problems that are noted to provide CA public utilities with technical information for their customers. A secondary objective is to quantify the potential annual savings a center that currently uses air economizers in order to encourage broader use. Preliminary results are encouraging in that low concentrations of contaminants have been found in both operating scenarios and no humidity control problems have been identified. A total of 6 or 7 centers in various climate zones will be studied. Research is also being planned, in collaboration with ASHRAE, to investigate the types of contaminants that could cause damage to IT equipment in larger concentrations. [more information]

Two individuals standing in front of fusible link curtains.

Wireless Temperature Sensors for HVAC Control

A wireless network of sensors has been deployed at the California Franchise Tax Board in Sacramento, CA, to control environmental conditions (temperature and humidity) in conjunction with variable-speed drives and hot/cold aisle isolation in the computer room for improved HVAC control. [more information]

Server Temperature Sensors for HVAC Control

Chart of POC Device Point Trends (rack top)

Control software and wireless sensors designed for closed-loop, monitoring and control of IT equipment's inlet air temperatures in datacenters were evaluated and tested while other datacenter cooling best practices were implemented. The controls software and hardware along with each best practice were installed sequentially and evaluated using a measurement and verification procedure between each measure. [more information]

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