cold air containment · mikko pervilä & jussi kangasharju 18.8.2011 2 reseach goals 1)reduce...

www.helsinki.fi/yliopisto

Cold Air ContainmentGreen Networking Workshop at SIGCOMM 2011

Friday, August 19th, 2011

Mikko Pervilä and Jussi Kangasharju

Mikko Pervilä & Jussi Kangasharju 218.8.2011www.helsinki.fi/yliopisto

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


source: Urs Hoelzle, European DC Summit 2011* source: GeSI/The Climate Group: SMART 2020** source: NRDC

72%

http://www.youtube.com/watch?v=SB7b8TeIkp8

http://www.google.com/corporate/datacenter/events/dc-summit-2011.html

Mikko Pervilä & Jussi Kangasharju 418.8.2011www.helsinki.fi/yliopistosource: Joe Kava, European DC Summit 2011

Materials: Steel and plastics

http://www.youtube.com/watch?v=APynRrGuZJA

http://www.google.com/corporate/datacenter/events/dc-summit-2011.html


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”

http://www.patentgenius.com/patent/7841199.html

http://h10134.www1.hp.com/insights/whitepapers/downloads/air_stream_containment.pdf


Mixed air flows

Ra

ck

Ra

ck

CR

AC

Side view

Raised floor


Separate air flows

Side view

Ra

ck

Ra

ck

CR

AC

Plastic wrap


Case: CERN

● “Flagship” installation

● Video from visitor area of CERN's DC

● http://www.youtube.com/watch?v=x5rmtSpuSGA

http://www.youtube.com/watch?v=x5rmtSpuSGA


Just buy it?

● Too much rebuilding

● New racks, reinstall everything


Just build a CFD?

● Computational Fluid Dynamics model

● Complex = expensive

● Google's modelling several (4+) iterations

● Cost: 5-10 k$


Real implementation

● Our costs 120.65 € in total:

● Plastic covers 29.50 €

● PVC tubes 37.14 €

● Duct tape 54.01 €

● Built in 3 hrs bythree persons

● Some cornerswere cut


Before changes

Typical DC evolution→

Inefficient placement?


Computer Room A/C (CRAC)

Engineering solution: add more power


Chilling plant

And more chilling plants.


Two chilling plants

Sharedchilling plant

Dedicatedchilling plant


Data CenterBK117

Ukk

o

CR

AC

CR

AC

CR

AC

CR

AC

CR

AC

sto

rag

e

HIIT

CS

De

pt.


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


Week before 26.3.2011

Ukko cluster

Total

Storage, HIIT, CRAC, UPS

CS Dept.

1 hour


Rising ambient temperature

Inlet temperatures from one hostAbsolute values suspect, relative change correct


Finished installation

ﾧ

after_CAC_installation.mp4http://www.youtube.com/watch?v=jZIuJIVYsDs

http://www.youtube.com/watch?v=jZIuJIVYsDs


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


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!


But power...

2 kW drop

Real savings at the chilling plant(s)?

Ukko cluster

Total

Storage, HIIT, CRAC, UPS

CS Dept.


Cooling fluid measurements

Set pointunchanged

Set pointraised by 7 °C

Cooling fluidmeasured here.Valves (W, S)


Before change, valve W

Periodic dropsof temperature


After change, valve W

Almost stabletemperature


Before change, valve S


After change, valve S


Pressure differences

● Inefficient placementstrikes back

● Less aisles is better

● sock_video.mp4● YouTube link

http://www.youtube.com/watch?v=m8NcIN4rNqU


“Finalized” version

● Switch to hard plastic sheets (video)

● http://www.youtube.com/watch?v=8-uybY91f4o

● Extra cost: ~260 €

http://www.youtube.com/watch?v=8-uybY91f4o


Reseach goals

1) Reduce cooling requirements (this talk)

2) Produce cooling for free (GreenNet 2010)

3) Harvest exhaust heat (?)

...With minimal rebuilding = cheaply


Last year at GreenNet


Helsinki Chamber (HC)

- rack servers- much more heat- improved air flow- more reflective

+ CAC prototype!


…And then we built that


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


Questions?

Pictures by● Janne Ahvo

● TuomasPuikkonen

● SebastianSiikavirta

Thanks!

Clear plastics are safe!

cold air containment · mikko pervilä & jussi kangasharju 18.8.2011 2 reseach goals 1)reduce...

Documents