energy savings in cerns main data centre
DESCRIPTION
Overview of CERN’s Data Centre Cooling system for main room Summary Overview of CERN’s Data Centre Cooling system for main room Situation before 2008 Improvements since 2008 Foreseen further improvements Energy savings Conclusions Energy Savings in CERN’s Main Data Centre - 2TRANSCRIPT
Energy Savings in CERNs Main Data Centre
Vincent Dor & Wayne Salter IT Computing Facilities Group Mauro
Nonis & Sabri Masrie EN Cooling and Ventilation Group Overview
of CERNs Data Centre Cooling system for main room
Summary Overview of CERNs Data Centre Cooling system for main room
Situation before 2008 Improvements since 2008 Foreseen further
improvements Energy savings Conclusions Energy Savings in CERNs
Main Data Centre - 2 CERNs Main Data Centre
Data centre built in early 1970s Has been refurbished/upgraded
several times Has three main computer rooms: 1440m2 main room with
air cooling 1240m2 basement room mixture of air/water cooling 225m2
room for critical servers only with water cooling Data B/U in a
separate building 3.5 MW available for computing equipment Energy
Savings in CERNs Main Data Centre - 3 Main Room Cooling
System
3+1 chillers (each 1.45 MW) 9+1 AHUs just under roof Cold air
passes down through large ducts and under the false floor Enters
cold aisle through perforated tiles Server fans draw the air though
the servers Exiting hot air sucked out via the false ceiling Energy
Savings in CERNs Main Data Centre - 4 Situation before 2008 From
70s to 90s mainframes Early 00s tower PCs
In 2007 started with rack mounted PCs No hot/cold aisle separation
Inefficient cooling High energy consumption Not possible to
properly cool in the summer Energy Savings in CERNs Main Data
Centre - 5 Installation of cold corridors (2008)
Enclosed cold aisles Doors from rack supplier Roof made at CERN
Strict hot/cold air separation All servers comfortably cooled even
during very hot weather Unfortunately energy savings from this are
not known Energy Savings in CERNs Main Data Centre - 6 Optimisation
of air distribution (2010/2011)
Analysing and modifying the operation of AHUs to increase the use
of free cooling by improving measurement and implementing full
automation of air intake and mixing reducing the intake of hot
exhaust air modifying the anti-freeze protection Maximum server
inlet temperature increased from 25 C to 27 C (ASHRAE) Set points
increased temperature of air produced by AHUs increased in steps
from 14 C to 22 C temperature of chilled water circuit increased
from5 C to 8 C Thermal analysis Energy Savings in CERNs Main Data
Centre - 7 Other measures since 2011 Improved monitoring
Identified and fixed leaks between the hot and cold plenums Now
able to run with 4 from 10 AHUs switched off Investigate the
possibility to change the fixed speed motors of the AHUs to
variable speed motors Allow better control of the flow rate to meet
actual needs Introduction of water cooled racks; first active and
now passive Increasing power density per rack Energy Savings in
CERNs Main Data Centre - 8 What are the energy savings?
Not known exactly! Missing important monitoring data before 2010
Chillers are used not only for main room but also for other rooms
Nevertheless we estimate for the changes made in 2010/2011 for the
main room With DC load of 2.6 MW and 1.9 MW in main room Annual
power consumption of chillers decreased from 6.5 GWh to 1.4 GWh PUE
for the entire DC reduced from 1.7 to 1.5 Switching off 3 AHUs (40
kW each) saves an additional 1.1 GWh Chiller Energy Consumption For
Main Computer Room July Nov Feb Jan Energy Savings in CERNs Main
Data Centre - 9 Thanks to the CERN EN/CV Group.
Conclusion Data centre built during mainframe era Has needed to be
adapted to changing computing technologies Major improvements have
been made: Installation of hot/cold aisles More complete use of
free cooling More aggressive temperature environment Impressive
energy savings achieved through fairly simple measures Further
measurements are continually being sought Thanks to the CERN EN/CV
Group. Energy Savings in CERNs Main Data Centre - 10