Cold Air Containment Green Networking Workshop at SIGCOMM 2011 Friday, August 19th, 2011 Mikko Pervilä and Jussi Kangasharju
Reseach goals 1) Reduce cooling requirements (this talk) 1) A/C performance 2) Chilling plant performance 2) Produce cooling for free (GreenNet 2010) 3) Harvest exhaust heat (future work)...with minimal rebuilding = cheaply 2
72% source: Urs Hoelzle, European DC Summit 2011 * source: GeSI/The Climate Group: SMART 2020 ** source: NRDC 3
Materials: Steel and plastics source: Joe Kava, European DC Summit 2011 4
Cold Air Containment VanGilder's patent filed in 2005: Cold Aisle Isolation HP's white paper: Hilss and Iyer, Improved data center efficiency incorporating air stream containment, 2009 (URL) Emulation-based, details omitted 14% to 41% efficiency improvements 5
Rack Rack CRAC Mixed air flows Raised floor Side view 6
Rack Rack CRAC Separate air flows Plastic wrap Side view 7
Case: CERN Flagship installation Video from visitor area of CERN's DC http://www.youtube.com/watch?v=x5rmtspusga 8
Just buy it? Too much rebuilding New racks, reinstall everything 9
Just build a CFD? Computational Fluid Dynamics model Complex = expensive Google's modelling several (4+) iterations Cost: 5-10 k$ 10
Real implementation Our costs 120.65 in total: Plastic covers 29.50 PVC tubes 37.14 Duct tape 54.01 Built in 3 hrs by three persons Some corners were cut 11
Before changes Typical DC evolution Inefficient placement? 12
Computer Room A/C (CRAC) Engineering solution: add more power 13
Chilling plant And more chilling plants. 14
Two chilling plants Dedicated chilling plant Shared chilling plant 15
HIIT Ukko CS Dept. storage CRAC CRAC CRAC CRAC CRAC Data Center BK117 16
Power draws 75 kw max power draw of Ukko cluster 55 kw cooling equipment installed in 2010 6,9 kw of Computer Room A/C (CRAC) units 44,7 kw chilling plant 3,8 kw rooftop radiator IT + CRAC load 85 kw typical 115 kw sustained peaks 17
Week before 26.3.2011 1 hour Total Ukko cluster Storage, HIIT, CRAC, UPS CS Dept. 18
Rising ambient temperature Inlet temperatures from one host Absolute values suspect, relative change correct 19
Finished installation ﾧ after_cac_installation.mp4 http://www.youtube.com/watch?v=jziujivysds 20
Effects on Ukko Two 16 h periods before and after Before: 7 hrs normal, 9 hrs peak load After: 9 hrs peak, 7 hrs normal load 21
Less cooling needed Same time periods as before Two CRAC:s kept on same set point Two CRAC:s adjusted up by 7 C One CRAC shut off completely! 22
But power... Total Ukko cluster 2 kw drop Storage, HIIT, CRAC, UPS CS Dept. Real savings at the chilling plant(s)? 23
Cooling fluid measurements Set point raised by 7 C Set point unchanged Cooling fluid measured here. Valves (W, S) 24
Before change, valve W Periodic drops of temperature 25
After change, valve W Almost stable temperature 26
Before change, valve S 27
After change, valve S 28
Pressure differences Inefficient placement strikes back Less aisles is better sock_video.mp4 YouTube link 29
Finalized version Switch to hard plastic sheets (video) http://www.youtube.com/watch?v=8-uyby91f4o Extra cost: ~260 30
Reseach goals 1) Reduce cooling requirements (this talk) 2) Produce cooling for free (GreenNet 2010) 3) Harvest exhaust heat (?)...With minimal rebuilding = cheaply 31
Last year at GreenNet 32
Helsinki Chamber (HC) - rack servers - much more heat - improved air flow - more reflective + CAC prototype! 33
And then we built that 34
Summary Cold Air Containment optimizes cooling Can now install 20% more load A/C can take it Chilling plants can take it(?) Tent and HC demonstrate free cooling Next project: Harvesting exhaust heat 35
Questions? Pictures by Janne Ahvo Tuomas Puikkonen Clear plastics are safe! Sebastian Siikavirta Thanks! 36