Emerging Technologies Demonstrations

1
BEST PRACTICES for ENERGY EFFICIENT DATA CENTERS
INDENTIFIED THROUGH CASE STUDIES and
DEMONSTRATION PROJECTS
Authors William Tschudi, Lawrence Berkeley
National Lab Stephen Fok,
Pacific Gas and Electric Company Presented
at ASHRAE Winter Meeting in Dallas,
Texas January 31, 2007
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BEST PRACTICES for ENERGY EFFICIENT DATA CENTERS
INDENTIFIED THROUGH CASE STUDIES and
DEMONSTRATION PROJECTS

• Northern California service territory including
  the Silicon Valley
• Estimated 400-500 MW of Data Center electricity
  load in our service territory
• Partnering with LBNL in addressing Data Center
  Energy Efficiency Opportunities Emerging
  Technologies
• In 2006, major utility EE Program Implementation
  produced 132 MW and 677 GWh in Electricity Savings

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BEST PRACTICES for ENERGY EFFICIENT DATA CENTERS
INDENTIFIED THROUGH CASE STUDIES and
DEMONSTRATION PROJECTS

• OVERVIEW
• LBNL Data Center Benchmarking - Roadmap
• Best Practices and Design Guidelines Sourcebook
• Air Management Demonstration
• Air Economizer Demonstration
• Centralized Air Handling Case Study
• Free Cooling using Water-Side Economizer Case
  Study
• Efficient Uninterruptible Power Supplies Case
  Study
• QA

4
LBNL Data Center Benchmarking
A research roadmap was developed for the
California Energy Commission and outlined key
areas for energy efficiency research,
development, and demonstration
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LBNL Data Center Benchmarking

• 23 Data Center Case Studies -
• Banks/financial institutions
• Web hosting
• Internet service provider
• Scientific Computing
• Recovery center
• Tax processing
• Storage and router manufacturers

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LBNL Data Center Benchmarking -IT equipment load
density
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Benchmarking energy end use
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Overall power use in Data Centers
Courtesy of Intel Corporation
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Data Center performance differences
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HVAC system effectiveness
We observed a wide variation in HVAC performance
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Best Practices topics identified through
Benchmarking
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CA utility Design Guidelines Sourcebook
Guides available through Energy Design Resources
Website
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Air Management Demonstration
Goal Demonstrate better cooling and energy
savings through improvements in air distribution
in a typical and a high density environment.
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Air Management Demonstration High Density Data
Center

• The as-found conditions were monitored
• Temperatures
• Fan energy
• IT energy
• An area containing two high-intensity rows and
  three computer room air conditioning units was
  physically isolated from rest of the center
  approximately 175 W/sf

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Air Mgmt Demo, High Density Data Center - (First
alternate) ColdAisle Isolation
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Air Mgmt Demo, High Density Data Center -
(Second Alternate) Hot Aisle Isolation
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Air Mgmt Demo, High Density Data Center -
Procedure

• Once test area was isolated, air conditioner fan
  speed was reduced using existing VFDs
• Temperatures at the servers were monitored
• IT equipment and fan energy were monitored
• Chilled water temperatures were monitored
• Hot aisle return air temperatures were monitored
  ?T was determined

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Air Mgmt Demo, High Density Data Center - Fan
energy savings 75
Since there was no mixing of cold supply air with
hot return air - fan speed could be reduced
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Air Mgmt Demo, High Density Data Center - Better
temp control would allow raising the temp in the
entire data center
ASHRAE Recommended Range
Ranges during demonstration
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Air Mgmt Demo, High Density Data Center

• Since air is not mixing, the overall air supply
  temperature could be raised (typically centers
  are below ASHRAE recommended minimums because of
  mixing)
• Hotter air is returned to the computer room air
  conditioners - Larger temperature difference (?T)
  allows air conditioning unit to have more
  capacity

21
Air Economizer Demonstration

• Goal encourage use of outside air economizers
  where climate is appropriate
• Strategy
• address data center professionals biggest
  concerns contamination and humidity control
• quantify energy savings at one center

22
Air Economizer Demonstration

• Total of EIGHT data centers were studied.
  Snapshot/monitoring over several days
• Continuous monitoring equipment in place at one
  center. Data collection over several months
• Before and after capability at TWO centers
• Energy savings estimate based on utility billing
  records.

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Air Economizer Demonstration

• Water soluble salts in combination with high
  humidity can cause failures
• Static electricity can occur with very low
  humidity
• Humidity control for make-up air (or no controls)
  is usually sufficient
• Particle concentrations with normal filtration
  are orders of magnitude lower than recommended
• Site No. 8 energy savings was estimated to be
  about 1 of total energy depending on economizer
  set point.

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Air Economizer Demo - Contamination is orders of
magnitude less at servers
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Air Economizer Demo - Particle Concentrations by
Size
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Centralized Air Handling Case Study

• Utilize larger more efficient fans and motors
  vs CRAC
• Use of variable frequency drives
• Located outside of the data center enhances space
  allocation and maintenance of IT equipment

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Free Cooling using Water-Side Economizer Case
Study

• Best suited for climates with wet bulb temp lt 55
  deg F for gt3000 hrs per year
• Very effective for chilled water systems designed
  for gt50 deg F
• Possible chilled water plant energy savings of up
  to 75

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(1) At the same level of redundancy, approx 5
efficiency gains is possible from operating the
UPS at 33 vs 25 of full load(2) Additional
HVAC savings improves life cycle costing
Efficient Uninterruptible Power Supplies Case
Study
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Best Practices for Energy Efficient Data Centers
Identified through Case Studies and Demonstration
Projects - Q A

• William Tschudi, P.E.
• E-Mail WFTschudi_at_lbl.gov
• Stephen Fok, P.E.
• E-Mail skf2_at_pge.com