apc multiple cooling issues with rack & inrow solutions

Addressing multiple cooling challenges with rack and row cooling architecture

Presented by: Kevin DunlapDirector, Business Strategy - Cooling

© 2006 American Power Conversion Corporation. All rights reserved. All trademarks provided are the property of their respective owners.

The problem

Result: an impossible planning challenge Result: an impossible planning challenge

Rack power densities of up to 30kW or more per rack30kW or more per rack thermally challenge traditional data centers that were designed for an average of 3kW per rack

Data center lifetime will span refresh cycles involving unknown unknown load and therefore heat profilesload and therefore heat profiles

Newer IT equipment exhibits dynamic power variationdynamic power variation where power and heat output vary more than 3:1 over time

Pushing traditional data centers to achieve high density reduces the efficiency of air conditioners, unnecessarily unnecessarily driving up electricity usedriving up electricity use

Users cannot predict cannot predict if the designed-in cooling redundancy of their system will actually work


Cooling ChallengesIncreasing Densities

Rack loads may vary from 2-30 kW in the same environmentA scalable cooling solution to handle future densities

Efficiency StrainNot addressing increased heat load can result in reduction of server efficiency

- Pull back on processing power- Increase in server fan speed

2006 Average= 6-8 kW rack

Fewer Instructions per Watt !!!

Source: IDC


Drivers for Energy Efficient Cooling

Real estateEnergy efficient infrastructure allows more space for ITCompaction of IT equipment

Increasing energy costsCommercial costs as high as $.13 kW/hour

Maximizing the investment in IT equipmentLowering the kW entering the data center for every 1 kW consumed by ITMaximizing the computing per watt (Mips/kW)

Power AvailabilityLimits on available power for new and existing data centers40% of end users claiming that demand is greater than supplyNew power generation is only 1.3% increase per year

Source: U.S. Department of Energy, IDC


Inefficient Response to Drivers

Supply colder air to the roomThis lowers the return air and reduces the actual cooling capacityIncreases moisture removal which must be added back to the room

Adding Units to Increase CapacityMay slightly address some heat issues at an electrical cost

These Cost Money and Don’t These Cost Money and Don’t Solve the Problem: Air Solve the Problem: Air DistributionDistribution


Cooling Challenges Not Limited To Data Center

IT/Wiring ClosetsVOIP and POE driving up densities

Space not designed for high heat loads5-7 watts/ft2 as office space50-100 watts/ft2 as wiring closet or small data center


Solutions for Wiring Closets and Small Computer Rooms

InRow SCSelf Contained 5 kWHeat rejected to plenum

Ventilation UnitAirflow enhancerPromotes circulation


Same racks, same room, slightly different cooling design

Totally different cooling airflow results!Current approaches provide unpredictable performance


High density cooling systems of the future

Rack-mount IT equipment will continue to be air cooled for the foreseeable futureRow or cabinet based distributed cooling systems will be used to scavenge hot air closer to the IT equipmentThe cooling technology at the row and cabinet level will be water or refrigerant basedThis equipment will be modular and will not fundamentally require a raised floor

The legacy raised floor cooling architecture will be superseded for high density applications by more

predictable and efficient approaches


Alternative cooling architecturesMethod Application Density

Traditional room-oriented raised floor cooling

Low densityVery flexible

1-5kW per rack

Medium densityGeneral use

Very high densityTargeted zonesAssured redundancy

Very high density specific racksMix of very high and low density

In-row 3-15kW per rack

In-row with hot aisle containment

10-25kW per rack

Rack-coupled 20-45kW per rack


Close Coupling: In-row approach (InRow RC)

InfraStruXure Cooling Distribution Unit

½ Rack form factor20kW ratingN+1 hot-swap variable speed fansCaptures hot air exhaust from nearby IT racksOverhead or under-floor pipingWorks with any brand of IT cabinetAdd units for redundancy or density


InRow RP

Full Rack In-RowChilled water or refrigerantVariable speed fansVariable capacity compressor40-60 kWPrecision AC –Dehumidify/Reheat/HumidifierGlobal ProductIntegrated Management


Basic in-row design

InfraStruXure® InRow RC

InRow RCCan operate on hard floor or raised floor

Hot-aisle air enters from rear preventing

mixing Cold air is supplied to

the cold aisle

Heat captured and rejected to chilled

water

CFD model of in-row system:Modeling failure of one CRAC


In-row rack-coupled CRAC

InfraStruXure Cooling Distribution Unit

Bayed to adjacent IT racksUp to 40kW ratingN+1 hot-swap fansDirectly ducts hot air exhaust from connected IT rackFront may be open or ductedMix into existing legacy data centerAdd second unit for redundancy or capacity


Rack Air Containment System

Rack Air Containment System

Plan View


Hot Aisle Containment

Shared CapacityEase of RedundancyZoned approachRoom independence

Room-oriented cooling airflow patterns

Row-oriented cooling airflow patterns


Dynamic power of loads amplifies the problems

Measurement is futile: A cooling system with Measurement is futile: A cooling system with assured predictable performance is requiredassured predictable performance is required

Power consumption of new servers varies by 2:1 or morevaries by 2:1 or moredepending on computational load

The variation in server power means thermal output also varies thermal output also varies by 3:1 or moreby 3:1 or more

This means current data center temperatures tell you little about what the temperature will be minutes or hours from nowminutes or hours from now

CFD analysis or ASHRAE TC 9.9 testing will be useless in useless in determining the condition of your cooling system determining the condition of your cooling system

Users cannot predict cannot predict if the designed-in cooling redundancy of their system will actually work even if it works right noweven if it works right now


A Hybrid Approach to CoolingMost Data Centers will have a mix of heat densities and therefore cooling solutions

IT Refreshes happen every 2-4 years resulting in a mix of distributed IT assetsIT management of blades and storage deployments is often in clusters

- Concentrated high density loadsOlder server assets may be well served by room cooling units

d

Row-orientedRack-oriented

Room-oriented


What about installation and piping?

InfraStruXure® InRow RC

Water in the data center?

What about leaks and condensation?

Complicated installation?

Retrofittable to existing data center?


PEX/Aluminum laminated seamless piping

Joint-less bendsEliminate leaks

Flexible: Earthquake and impact resistant

Under-floor or overhead water distribution


Isolation and balancing valveAllows isolation for servicing and provides coolant flow adjustment

InfraStruXure® Cooling Distribution Unit

Coolant Distribution Unit (CDU)

Individual supply and return linesSupplies and returns coolant to and from CRAC units

Main supply and return headersSupplies and returns coolant to and from the Chiller

Top or bottom piping connectionsAllows the CDU to be top or bottom piped

Condensate pan with drain connection

CastersAllows the CDU to be installed easilyIsolation valve

Allows isolation for servicing


Typical piping layout


Cooling becomes more like power!

Power CoolingPower

Distribution UnitCoolant

Distribution Unit

Power Whips Cooling “Whips”


More Information

#130#130 The Advantage of Row and Rack-Oriented Cooling Architectures for Data Centers

#131#131 Improved Chilled Water Piping Distribution Methodology for Data Centers

#125#125 Strategies for Deploying Blade Servers in Existing Data Centers

#43#43 Dynamic Power Variations in Data Centers and Network Rooms

For further information on these topicsconsult APC white papers on

www.apc.comwww.apc.com

apc multiple cooling issues with rack & inrow solutions

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