data center thermal management and efficiency
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Data Center Thermal Management and Efficiency. Jay Ries Regional Sales Manager Liebert Thermal Management Emerson Network Power . Agenda. Where is energy consumed in the data center? Energy consumption example Cooling energy consumption breakdown Strategies for saving energy - PowerPoint PPT PresentationTRANSCRIPT
Data Center Thermal Management and Efficiency
Jay RiesRegional Sales ManagerLiebert Thermal ManagementEmerson Network Power
AgendaWhere is energy consumed in the data center?Energy consumption example
– Cooling energy consumption breakdownStrategies for saving energy
– Low cost strategies– Medium cost strategies– Higher cost strategies
Taking it a step further (beyond cooling)Summary
3
Where is Energy Consumed in the Data Center?
Proce
ssor
Other S
ervic
es
Server P
ower
Supp
ly
Storage
Communic
ation E
quipmen
t
Coolin
gUPS
MV Tra
nsform
er an
d Switc
hgea
r
Lighti
ngPDU
0%
5%
10%
15%
20%
25%
30%
35%
40%
48% is consumed by power and cooling
support
52% is consumed by IT equipment
Energy Consumption ExampleEnergy Consumption ExampleBaseline Building design
Existing building− Limitation to physical changes that can be made− Best suited for modifications to existing equipment− Full equipment replacement is a last resort
1MW of facility power usage (all data center)
Baseline Cooling design Centrifugal water cooled chiller No economization Standard computer room cooling units
− No variable speed fans or advanced controls− Return air control− 45° F chilled water − 72° F return air, 50% RH
Energy Consumption ExampleEnergy Consumption ExamplePower UsageProcessors – 150kWOther Services – 150kWServer Power Supply – 140kWStorage – 40kW Communication Equipment – 40kW
Cooling – 380kWUPS – 50kWMV Transformer and Switchgear – 30kWLighting – 10kWPDU – 10kW
IT Power Usage = 520kWSupport Power Usage = 480kWTotal Facility Power Usage = 1000kWAnnualized Facility PUE = 1.92 Work our way to 1.35
Cooling is the only area that will be modified. In the real world, each variable will have an impact on the others
Cooling Energy Consumption BreakdownAir Cooled System Water Cooled System
Chilled Water System
Low Cost Strategies1. Implementing best practices2. Adjust the unit control methods
– Dew point control– Unit operating range
3. Change to supply air control4. Running at higher chilled water temperatures
If you have a raised floor, use it properly. Underfloor resistance wastes energy.
Utilize hot aisle / cold aisle, regardless if you have a raised floor
Low Cost Strategies1. Implementing Best Practices
Get air where it is supposed to go.– Blanking panels– Fix unplanned outside infiltrations and any unecessary gaps in the
raised floor– Return plenums to the cooling unit
Isolate the room, particularly if you want to control humidity
Low Cost Strategies1. Implementing Best Practices
Dew Point– Standard design points used to be 72° return air temperature
and 50% relative humidity (RH)– New, more aggressive design points can be 90°+ return air
temperature and an unspecified relative humidity– Why shouldn’t you fix at 50% relative humidity (RH)
• Dew point @ 72°, 50% = 52°• Dew point @ 95°, 50% = 74°
– If the return temperature is increased at a fixed RH, the dew point will rise, requiring the equipment to waste energy to remove moisture that didn’t need to be there in the first place
Low Cost Strategies2. Adjust Unit Settings
Unit operation settings– Expanding the operating range for the temperature and
humidity keeps unit components from cycling too frequently.– Higher return air temperatures allow CRAH units to run
more efficiently• Capacity increase up to 70% for chilled water units• Capacity increase up to 50% for compressor based units• The more efficiently the units operate, the fewer that are
required to control the space, saving energy.
Low Cost Strategies2. Adjust Unit Settings
Low Cost Strategies2. Adjust Unit Settings
Increased Capacity at Higher Temps
Supplies a consistent temperature to the cold aisle Saves energy because it allows the return air temperature to be
increased, allowing the CRAH unit to run more efficiently.
Low Cost Strategies3. Supply Air Control
45° chilled water temperature has been the standard design point for many years
Higher chilled water temperatures are starting to become more prevalent
Why? At higher temperatures, there are huge potential savings on the chiller – For every 1 degree increase in the chilled water supply temperature, a
2% energy savings can be realized on the chiller plant– 45°chilled water = Baseline– 55°chilled water = 20% energy savings
Low Cost Strategies4. Running At Higher Water Temperatures
Low Cost StrategiesThe Results of Implementation
Applying Low Cost Strategies– Changes to cooling system
• Best practices implemented• Supply air control• 50° F chilled water• 85° F return air with dew point control
Support Power Usage = 480kW Total Facility Power Usage = 1000kW Annualized Facility PUE = 1.92
Total cooling power usage drops from 380kW to 314kW. The number of units stay the same, but
some units can be turned off.
414kW934kW
1.79
Medium Cost Strategies1. Variable speed fan retrofits (EC Fan / VFD)2. Aisle containment3. Control retrofits4. Rack level sensors
Floor-mount cooling fans typically run at 100% rated rpm By utilizing variable speed technology, fan speed can be varied based
upon room conditions Energy savings based on a single 10HP motor
18
Fan Speed Energy
Consumed
Savings100% 8.1kWH
90% 5.9kWH 27%
80% 4.2kWH 48%
70% 2.8kWH 65%
60% 1.8kWH 78%
Medium Cost Strategies1. Variable speed fan retrofits (EC Fan / VFD)
Medium Cost Strategies2. Aisle Containment
Allows for proper air separation Able to be done either the hot or cold aisle, though it is easier to
retrofit the cold aisle of an existing room Physical containment varies from simple curtains to a pre-fabricated
system designed to match the racks.
Containment Strategies Contained hot aisle
– Requires full containment to trap hot air– Can be difficult to retrofit in perimeter designs– Easier to retrofit in row cooling designs– Overhead fire suppression concerns on full containment
Contained cold aisle– Multiple containment options
• Doors only• Curtains only• Full containment
– Can be easier to retrofit in all cooling designs– Overhead fire suppression concerns on full containment
Medium Cost Strategies2. Aisle Containment
Medium Cost Strategies3. Control Retrofits
Allows for upgraded control schemes that save energy New controls allow units to be networked together
– Give more visibility of full system– Eliminate fighting of units, - one cooling while one is heating
Usually associated with a control retrofit or a designed scheme through a building management system
Increased visibility and quicker reaction to changes at the rack Generally applied with supply air sensors
“Bath tub effect”
Medium Cost Strategies4. Remote Sensors
Low + Medium Cost StrategiesThe Results of ImplementationApplying Low + Medium Cost Strategies
Changes to cooling system• Best practices implemented• Supply air control• +55° F chilled water• +90° F return air with dew point control• + Remote sensors• + Aisle containment• + Variable speed fans• + Control retrofits
Support Power Usage = 414kW Total Facility Power Usage = 934kW Annualized Facility PUE = 1.79
Total cooling power usage drops from 314kW to
184kW. All units are now on, running at a reduced
speed.
284kW
804kW1.55
ROI is generally less than 1 year for these strategies
Higher Cost Strategies (Major Capital Expenditures)
1. Bringing cooling closer to the source
2. Variable capacity compressors
3. Economization– Air economizers
– Water economizers
– Refrigerant Economizers
Bring the cooling closer minimizes the need for large fans, reducing energy
Some rear door designs don’t have fans, instead utilizing the server fans to move the air
Generally produce a better sensible cooling to power ratio than a typical system – more cooling for less energy
Row-based configuration
Rack-based configuration
Rear door configuration
Higher Cost Strategies1. Bringing Cooling Closer to the Source
Base Infrastructure (160 kw) Cooling Modules (mix and match)
Dew Point Controlled Pumped Refrigerant Cooling
Higher Cost Strategies1. Bringing Cooling Closer to the SourceRack Based Solutions Pump Refrigerant Technology
Refrigerant Based Rear Door• Refrigerant based, rear door heat exchanger• A rear door with 10kW to 40kW of cooling• Connect up to 16 doors onto a single pumped refrigerant loop• Designed to accommodate various racks• Energy story – passive door (no fans) that uses the server fans
to transfer air through the coil
Performance• Provides room neutral high density rack cooling• Applicable for atypical room layouts and rooms without hot
aisle / cold aisle configuration
Rear Door Solutions
Higher Cost Strategies1. Bringing Cooling Closer to the Source
Chilled Water Based Rear Door• Chilled water based, rear door heat exchanger• A rear door with 16kW to 35kW of cooling• Designed to accommodate various racks• Energy story – passive door (no fans) that uses the server fans
to transfer air through the coil
Performance• Provides room neutral high density rack cooling• Applicable for atypical room layouts and rooms without hot
aisle / cold aisle configuration
Rear Door Solutions
Higher Cost Strategies1. Bringing Cooling Closer to the Source
Row Based Solutions• Precise temperature and Humidity control• 12” or 24” wide designs• Air, Water, Glycol and Chilled Water models• Energy efficient, load matching
- Digital scroll compressor, 20-100% cooling capacity modulation- Variable speed EC plug fans
Performance• Real-time environment control• Automatic performance optimization• Adaptive component monitoring• Adjustable air baffle direction
Row Based Solutions
Higher Cost Strategies1. Bringing Cooling Closer to the Source
Fan Energy for 30kW of Cooling
Higher Cost Strategies1. Bringing Cooling Closer to the Source
Row-based configuration
Rack-based configuration
Rear door configuration
Perimeter Unit = 4.24 kW
Row-Based Unit = 1.38 kW
Rack Based = 0.54 kW
Rear Door = 0.00 kW (no fans)
Digital Scroll Compressors– Matches room load in unlimited step increments– Reliable – Not field repairable. Must be replaced.
4-step Semi-Hermetic Compressors– Matches room load in 4 step increments– Reliable – Field repairable
Compressors w/ VFD Control– Matches room load in unlimited step increments– Reliable– Usually not field repairable.
Higher Cost Strategies2. Variable Capacity Compressors
Intended for partially loaded rooms. May be used in conjunction with variable speed fans
for even greater energy savings.
Air side economizers– For chilled water or compressorized systems– Utilize outside air based on dew point,
minimizing compressor and/or chiller usage
Higher Cost Strategies3. Economization
Water side economizers For chilled water systems Uses water cooled by a cooling tower or a dry
cooler (fluid cooler) in low temperature conditions to minimize chiller operation
Pumped refrigerant economizers New technology for compressorized systems Uses refrigerant cooled in low temperature conditions
to minimize condenser and compressor operation Similar utilization as water side economizers
Liebert DSE with EconoPhase Pumped Refrigerant Economizer
Cooling PUE1.3 - 1.05
DX with Water-Side Economizer
Chilled Water with Air-Side Economizer
Liebert DSE with EconoPhase
0
50
100
150
200
250
300
350
400
450Annual Energy Usage
Ann
ual U
tility
Cos
t ($1
000’
s)
60%
Reliable, Low-Maintenance
OperationNo water usageNo water treatmentNo outside air
contaminationNo dampers and
louvers to maintainInstant, automatic
economizer changeover
Liebert DSE –The Most Efficient DX Data Center Cooling System
Higher Cost Strategies3. Economization – Pumped Refrigerant
Liebert DSE Indoor UnitNext generation data center cooling system
Liebert EconoPhaseFirst ever pumped refrigerant economizer Liebert MC
Intelligent, high efficiency condensers
Thermal System Manager with iCOM
Liebert Proprietary Data Center Management Intelligence and
Optimized Aisle
Liebert DSE System Overview
Higher Cost Strategies3. Economization – Pumped Refrigerant
8.5 kW
8.5 kW3.2 kW
3.9 kW
Check Valve
Compressor
EvaporatorElectronic expansion
valve
Check Valve
Check Valve
RefrigerantPump
SolenoidValve
Circuit 2
Circuit 1
DSE
MC Condenser
8.7 kW
8.7 kW
3.4 kW
4.1 kW
Liebert DSE System: DX Operation Mode
CoolingMode
OutdoorTemp
CoolingpPUE SCOP System
kW
DX 95º F 1.26 3.8 24.9
Check Valve
Compressor
EvaporatorElectronic expansion
valve
Check Valve
Check Valve
RefrigerantPump
SolenoidValve
EconoPhase
Circuit 2
Circuit 1
DSE
9.8 kW
0.0 kW
3.4 kW
0.3kW
3.9 kW
MC Condenser
0.1 kW
Liebert DSE System: DX + Pump Operation Mode
CoolingMode
OutdoorTemp
CoolingpPUE SCOP System
kW
DX 95º F 1.26 3.8 24.9
Partial 60º F 1.14 7.0 13.6
Check Valve
Compressor
EvaporatorElectronic expansion
valve
Check Valve
Check Valve
RefrigerantPump
SolenoidValve
EconoPhase
Circuit 2
Circuit 1
DSE
0.0 kW
0.0 kW
3.4 kW
0.4 kW
3.9 kW
MC Condenser
4.8 kW
Liebert DSE System:Pump Operation Mode
0.4 kW
CoolingMode
OutdoorTemp
CoolingpPUE SCOP System
kW
DX 95º F 1.26 3.8 24.9
Partial 60º F 1.14 7.0 13.6
Full 45º F 1.09 10.6 9.0
Check Valve
Compressor
EvaporatorElectronic expansion
valve
Check Valve
Check Valve
RefrigerantPump
SolenoidValve
EconoPhase
Circuit 2
Circuit 1
DSE
0.0 kW
0.0 kW
3.4 kW
0.5 kW
3.9 kW
MC Condenser
0.2 kW
Liebert DSE System:Pump Operation Mode
0.5 kW
CoolingMode
OutdoorTemp
CoolingpPUE SCOP System
kW
DX 95º F 1.26 3.8 24.9
Partial 60º F 1.14 7.0 13.6
Full 45º F 1.09 10.6 9.0
Full 30º F 1.05 20.7 4.6
Minneapolis, MN Bin Data – EconoPhase, Partial, Compressor
below 5
5 to 9 10 to 14
15 to 19
20 to 24
25 to 29
30 to 34
35 to 39
40 to 44
45 to 49
50 to 54
55 to 59
60 to 64
65 to 69
70 to 74
75 to 79
80 to 84
85 to 89
90 to 94
above 95
0
100
200
300
400
500
600
700
800
900
Dayton, OHGrand Rapids Michigan
1MW of IT load 90°F return air; 20% + redundancy; No humidity control Which is best? It depends on the customer drivers
– First cost/capital cost– Energy savings/PUE– Total cost of ownership– Redundancy/availability– Reliability
LIEBERT® DSE
Higher Cost Strategies3. Economization
Low + Medium + Higher Cost StrategiesThe Results of ImplementationApplying Low + Medium + Higher Cost Strategies
Key cooling system features• Supply air control• 90° F return air with dew point control• Rack level sensors• Aisle containment• Variable Speed Fans• Advanced Controls• + Pumped Refrigerant Economizers• + Variable Capacity Compressors
Support Power Usage = 284kW Total Facility Power Usage = 804kW Annualized Facility PUE = 1.55
Total cooling power usage drops from 184kW to 83kW.
All CW units have been replaced with new units.
183kW703kW
1.35ROI is generally less than 3 years for these strategies
Taking It a Step Further The annualized cooling PUE for cooling only is 1.09 for
the last scenario. Why is the overall PUE 1.35?– Not implementing virtualization with the servers– Inefficiencies in the power distribution:
• UPS modules• PDUs• Generators• Batteries• Switchgear• Lighting
– Lack of monitoring• Not having real time data means you cannot react quickly
Taking It a Step Further How can I get an even better cooling PUE?
– Raise water and air temperatures even higher– Implement alternate technologies that remove or greatly reduce
cooling
– Improve server monitoring
RISKPUE AVAILABILITY
PUESERVER LOADS
Implementing the StrategiesMultiple strategies to consider
– Low cost– Medium cost– Higher cost– Combination of any or all of the above
Implementing any of these strategies can be somewhat difficult– Where do I start?– What can I implement?
• Can the current equipment be upgraded?• Do I have budget for equipment upgrades?• Do I need outside help?
You don’t have to spend a fortune to get energy savings However, to get to a world class level, major changes generally have
to be made Total energy consumption needs to be considered along with PUE Focusing only on PUE can increase risk and availability
– Works with some data center models, but not for all
Summary
For more information on this topic, please check out the updated vendor neutral Energy Logic 2 white paper,
available on the Emerson Network Power website
