Energy Efficiency Tune-up of a Legacy Data Center
Geoffrey Bell, Lawrence Berkeley National Laboratory
The data center in Lawrence Berkeley National Laboratory's (LBNL's) Building 50, Room 1275, has a long and interesting history that stretches back several decades. The center originally housed large, air-cooled IBM computers. It was later reconfigured to support LBNL's payroll and other miscellaneous computing needs. In 1996, the National Energy Research Scientific Computing Center (NERSC) was located in this center. It used water-cooled Cray C-90 computers; in 1999, the Cray computers were replaced with new air-cooled computers. By July 2007, the data center had two types of datacom equipment: approximately 250 kilowatts (kW) of high-density research computing clusters and approximately 90 kW of "back-of-house" IT equipment.
A baseline energy-use assessment, and subsequent energy-efficiency retrofit analyses, began in July 2007. This assessment confirmed a baseline IT load approximate of 330 kW. With a cooling system capacity of 140 tons (nominal), it only just kept the servers cool. However, during the assessment period while some retrofit measures were being installed, the facility operators added approximately 100 kW of IT load. To further complicate matters, the IT staff was contemplating installing an additional 120 kW of IT load in the near future that would bring the total connected IT load to 550 kW.
With chiller capacity "maxed out" and no additional space
to locate additional cooling system capacity, installing efficiency measures
(EEMs) to increase the center's effective cooling capacity were the only
option for the LBNL staff. Three main EEM upgrades were identified that
resulted in reduced energy waste in the data center, effectively increasing
the existing system's cooling capacity as follows:
Retrofit Tune-Up Summary
1. Airflow optimization
- Rearranged floor tiles and sealed leaks
- Reconfigured supply and return ductwork
- Isolated hot and cold aisles
2. Wireless temperature sensors
- Improved control with real-time temperature data
3. Server rear-door heat exchangers
- Used treated tower water to prevent chiller energy use
- Eliminated fan energy with passive device
These upgrades have increased cooling capacity sufficiently to handle the anticipated final connected IT load of 550 kW.
This presentation will review three new DataCenters21 case study bulletins that summarize the retrofit tune-ups installed in the LBNL 1275 data center.
Biography:
Geoffrey Bell is an energy engineer in the Environmental Energy Technology Division at Lawrence Berkeley National Laboratory. He is credited with a number of publications, and served as a principal author of the Design Guide for Energy Efficient Laboratories. This publication is intended to assist facility owners, architects, engineers, designers, facility managers, and utility energy-management specialists in identifying and applying advanced energy-efficiency features in laboratory-type environments. Mr. Bell is a certified state energy auditor in New Mexico and a registered professional engineer in both New Mexico and California. He has served as an investigator for the U.S. Department of Energy, a teacher at the University of New Mexico, and an energy engineer contractor to Sandia Corporation, in addition to various other mechanical engineering consulting positions. Mr. Bell received his Bachelor of Science degree in mechanical engineering from Newark College of Engineering and a Master of Architecture degree in environmental design from the University of New Mexico.