Authors: William Tschudi, Lawrence Berkeley National Lab Stephen Fok, Pacific Gas and Electric Compan

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

2. 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

3. 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 • Q&A

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

5. 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

6. LBNL Data Center Benchmarking -IT equipment load density

7. Benchmarking energy end use

8. Overall power use in Data Centers Courtesy of Intel Corporation

9. Data Center performance differences

10. HVAC system effectiveness We observed a wide variation in HVAC performance

11. Best Practices topics identified through Benchmarking

12. CA utility Design Guidelines Sourcebook Guides available through Energy Design Resources Website

13. Air Management Demonstration Goal: Demonstrate better cooling and energy savings through improvements in air distribution in a typical and a high density environment.

14. 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

15. Air Mgmt Demo, High Density Data Center - (First alternate) ColdAisle Isolation

16. Air Mgmt Demo, High Density Data Center - (Second Alternate): Hot Aisle Isolation

17. Air Mgmt Demo, High Density Data Center - Procedure • Once test area was isolated, air conditioner fan speed was reduced using existing VFD’s • 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 – ΔT was determined

18. 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

19. 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

20. 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 (ΔT) 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 professional’s 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.

23. 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.

24. Air Economizer Demo - Contamination is orders of magnitude less at servers

25. Air Economizer Demo - Particle Concentrations by Size

26. 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

27. Free Cooling using Water-Side Economizer Case Study • Best suited for climates with wet bulb temp < 55 deg F for >3000 hrs per year • Very effective for chilled water systems designed for >50 deg F • Possible chilled water plant energy savings of up to 75%

28. (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

29. Best Practices for Energy Efficient Data Centers Identified through Case Studies and Demonstration Projects - Q & A William Tschudi, P.E.: E-Mail – WFTschudi@lbl.gov Stephen Fok, P.E.: E-Mail – skf2@pge.com