energy efficient data centre design 1 energy efficient data centre design presenter:tony de...

ENERGY EFFICIENT DATA CENTRE DESIGN 1

Energy Efficient Energy Efficient Data Centre Data Centre

DesignDesignPresenter:Presenter: Tony de Francesco Tony de Francesco B.Eng Mech (Hons. Class 1)B.Eng Mech (Hons. Class 1)

Systems EngineerSystems Engineer


Meet STULZ Worldwide

Since its founding in 1947, STULZ has specialised in areas requiring technological expertise and entrepreneurial flexibility.


STULZ Australia - Business Areas

As an air conditioning specialist STULZ offers a wide range of customer solutions for the high-tech areas of IT, telecommunications and automation.In conjunction with an extensive range of precision air conditioning units, STULZ also manufacture a range of internal and external chillers for precision and comfort applications.

Precision Air Condition Units Humidification Systems

• Standalone Steam Humidification• Ultrasonic Humidification

For Close Control Areas, such as• Museums,• Archives,• Art Galleries,• Storage Rooms,• Testing Laboratories, and• Process Areas.

STULZ also manufacture and supply equipment for cooling cabinets, industrial cooling and High DensityCooling Solutions.

High Density Cooling Solutions

STULZ provides 24/7/365 days aYear service and support through our factory trained service technicians, local spare parts and a range ofComprehensive ServiceAgreements.

National 1300 Support Hotline

Customer Service


TopicsTopics1.1. Room DesignRoom Design

2.2. CRAC Unit DesignCRAC Unit Design

3. CHW System Design3. CHW System Design


1. Room Design1. Room Design


Source: ASHRAE - Thermal Guidelines for data Processing Environments, pg 10


Source: HP

Rack Cooling Basics


22°C @ 50%RH

13°C @ 88%RH

35°C @ 23%RH

Typical Computer Room Air Distribution

Average, say 20°C @ 57%RH


Rack Cooling Example

20 racks @ 5 kW/rack = 100 kW

Therefore if, Q = 100,000 W

T = (35 – 20) = 15K

Let ρA x cPA = 1.21 kJ/m³K

ΔT

Required Air Flow Rate: V = 100,000 / (1.21 x 15)

=> 5,500 l/s total or275 l/s per rack

V Q


20 racksx 5kW ea

Q = 100kW

9200 l/s @ 22°C

9200 l/s @ 13°C

5500 l/s @ 35°C

5500 l/s@ 20°C

1750 l/s @ 35°C

3750 l/s@ 13°C

5450 l/s @ 13°C

3750 l/s@ 35°C

4.67 l/s @ 7°C

12.5°C

Power In: 7.2 kW @ 50Pa ESP

Power In:34 kW @

COP = 3.16

Total Power In = Fan Power + Chiller Power= 7.2 + 34

= 41.2 kW for 100 kW of rack load => η = 2.43

Typical Raised Floor Air Distribution Design


5500 l/s @ 35°C

5500 l/s @ 20°C

5500 l/s @ 35°C

5500 l/s@ 20°C

4.42 l/s @ 12°C

17.5°C

Power In: 1.8 kW @ 50Pa ESP

Power In: 27 kW @

COP = 3.77

Total Power In = Fan Power + Chiller Power= 1.8 + 27

= 28.8 kW for 100 kW of rack load => η = 3.47

30% Power

Reduction!

Smaller CRAC!Smaller Chiller!

Direct Rack Air Cooling

20 racksx 5kW ea

Q = 100kW


Source: ASHRAE - Datacom Equipment Power Trends and Cooling Applications, Page 34

Underfloor Supply Air Distribution



Ducted Return Air Distribution



Ducted Supply & Return Air Distribution


How Does It Work?Fan assisted system that draws air through rack from either the raised floor or from the cold isle and discharges the air out of the top of the door

Features• Airflow of 830l/s delivers ~15kW of cooling• Returns air back to room at high temp, say 35°C

Example: Stulz Rack Air Removal Unit



Liquid Cooled Racks


Stulz Liquid Cooled Rack Solutions

Racks designed for 10-22kW of heat load

RAWRear Door Air/Water Heat Exchanger

CyberChillIntegrated Rack Cooling Solution


CyberChill: Basic Function

cooling water connection


RAW Module: Basic Function – Closed Loop

cooling waterconnection

RAW Module mounts to the rear door of the rack of your choice


RAW Module: Basic Function – Open Loop

RAW Module mounts to the rear door of the rack of your choice

cooling waterconnection


Stulz Liquid Cooling Intrastructure


2. CRAC Unit 2. CRAC Unit DesignDesign


Cooling Capacity: What does total & net sensible mean?

Cooling Air13.7° C; 83 % r. H.8.1 g water / kg air

86 kW Net Sensible Cooling Capacity

9 kW Heat RejectionFan absorbed power

converted to heat

Temperature Increase 1.1° C

Return Air24° C; 45 % r. H.

8.4 g water / kg air

Airflow6,950 l/s

Total Cooling Capacity100 kW Total

95 kW Sensible Capacity(cooling)

and5 kW Latent Capacity

(dehumidification)

Temperature Decrease11.4° C

andHumidity Decrease

0.3 g / kgCooling Air

12.6° C; 89 % r. H.8.1 g water / kg air

Input ConditionsFunction


Effect of Supply Fan Efficiency

Traditional belt driven fan technologies can reduce the available cooling capacity by as much as 10%!

Up to 30% reduction in fan power can be achieved by using highest efficiency direct driven fan technologies in lieu of typical belt driven fans.

A reduction in fan power of only 1kW would result in an energy cost saving of over $1000 p.a. and reduction of 11.8 tonnes CO2/yr (@ $0.10//kWhr and COP = 4)


• Electronically commutated (EC) permanent

magnet DC motor

• Variable Speed Driven

• Rotary motion of the motor is achieved via

electronically switching device (electronic

commutator) and not via mechanical carbon

brushes and therefore wear-free requiring no

maintenance

• Efficiencies of up to 92%

EC Technology began almost 30 years ago in computer and telecom applications.

An EC motor is simply a DC motor without mechanical brushes and commutator rings.

High Efficiency Direct Driven EC Fans


• Reduced fan power provides increased real (net) cooling capacity and reduces load on refrigeration plant

• Variable airflow rate capability allows rates to be set at commissioning for optimum levels (rather than nominal levels)

• Non-Maintenable item: no v-belts or pulleys – Reduction of life cycle costs

• Inbuilt Softstart operation eliminating high inrush current. Particularly helpful in diesel generator mode.

Benefits of EC Fan Technology


Benefits if EC Fan Technology (DX Operation)

Data A.C Belt Driven FanEC Direct Driven

Fan

Airflow per Unit l/s 6,665 @ 20Pa 6,665 @ 20Pa

Cooling Capacity (Total) per Unit kW 101.5 101.5

Cooling Capacity (Sensible) per Unit kW 94.6 94.6

Compressor Power Consumption per Unit kW 22.0 22.0

Evaporator Fan Power Consumption per Unit kW 9.2 5.9

Condenser Fan Power Consumption per Unit kW 3.1 3.1

COP 4.6 4.6

EER 2.7 3.1

Operating Hours per Year per unit hrs 8,760 8,760

Energy Pricing $/kWhr $0.10 $0.10

Average Annual Compressor Operation 100% 96%

Total Energy Consumption kWhrs/yr 300,293 263,256

Comparative Energy Costs $/yr $30,029 $26,326

Comparative Savings in Energy Costs $/yr $3,704

Comparative Savings in CO2 tonnes/yr 40.0

Return Air Setpoint: 24°C @ 45%RH


Dual Fluid System

• Each individual CRAC unit has two independent cooling systems

• Possible cooling combinations include:

1. CHW / CHW

2. Water Cooled DX / CHW

3. Air Cooled DX / CHW

• Cooling mode can beoptimised to provide mostefficient method of cooling

• Dual fluid system alsoprovide increased levels ofredundancy


Office A/C

Office A/C

Office A/C

PrecisionA/C

Reduced energy consumption by sourcing chilled water from more efficient central plant whilst providing high operational safety/system availability

B/H Mode A/H ModeEmer.

OperationPeak Load Operation

Office A/C On Off Off On

Chiller On Off Off On

CHW Circuit On Off Off On

DX Circuit Off On On On

Compressor Off On On On

Condenser Off On On On

Benefits of Dual Fluid System

Example Operating Logic:


3. CHW System 3. CHW System DesignDesign


Typical Data Centre Configuration

CRAC 1CRAC 1 CRAC 2CRAC 2 CRAC 3CRAC 3 CRAC 4CRAC 4


Duty / Standby Operation (N+1)

5,000 l/s5,000 l/s 5,000 l/s5,000 l/s 5,000 l/s5,000 l/s 0 l/s0 l/s

5,000 l/s5,000 l/s 5,000 l/s5,000 l/s 5,000 l/s5,000 l/s 5,000 l/s5,000 l/s

TOTAL: 35,000 l/s

TOTAL: 35,000 l/s


Optimal Data Centre Configuration



CHW Fan Management Mode (N+1)



TOTAL: 35,000 l/s

TOTAL: 35,000 l/s


Example:

3 x ASD1500CW

R/A = 24°C/45%

CHW = 7/12°C waterStandby

Airflow: 2 x 8,000 l/sFan absorbed power: 2 x 8.0 = 16.0 kWCombined noise (@2m): 2 x 65.1dBA = 68.1dBA

2 x 106.0 =212.0 kW net sensible

Benefits:

+ Energy savings

+ Reduced noise levels

+Improved air distribution

+ Dampers not required

Chilled Water Fan Management

3 x 70.7 = 212.1 kW net sensible

Airflow: 3 x 4,850 l/sFan absorbed power: 3 x 1.8 = 5.4 kWCombined noise (@2m): 3 x 54.5dBA = 59.3dBA

Annual Energy Savings: Fan Savings: 10.6 kW = $9,286/yr Est. Chiller Savings: 2.7 kW = $2,321/yr* Energy cost rate: 0,1 $/kWh & Chiller COP = 4

$11,607 / yr125 tonnes CO2 / yr


CASE STUDY: Westpac Data Centre

Data

Existing Units with Belt Drive

Centrifugal Fans EC Fan Technology EC Fan Technology

(N+2 Operation) (N+2 Operation) (Energy Saving Mode)

Total No. of Units Installed 9 9 9

No of Duty Units 7 7 9

Airflow per Unit (l/s) 4481 @ 100 Pa 5,055 @ 100 Pa 3,650 @ 100 Pa

Total Cooling Capacity (kW) per Unit 65.4 60.7 46

Sensible Cooling Capacity (kW) per Unit 62.8 60.7 46

Fan Power Per Unit (kW) 5.7 3.5 1.6

Net Total Cooling Capacity (kW) 418 400 400

Net Sensible Cooling Capacity (kW) 400 400 400

Total Airflow (l/s) 31,367 35,385 33,147

Total Fan Power (kW) 39.9 24.5 14.4

Refrigeration Power at system EER=4 (kW) 114.5 106.2 103.5

Total Power (kW) 154.4 130.7 117.9

Hours of Operation (h) 8,760 8,760 8,760

Total Energy Consumption (kWh) 1,352,106 1,145,151 1,032,804

Unit Energy Cost ($/kWh) 0.10 0.10 0.10

Annual Energy Cost ($) $135,211 $114,515 $103,280

Annual Energy Cost Difference ($) - -$20,696 -$31,930

Annual Reduction in CO2 (tonnes per year) - 223.5 344.8


Summary:Summary:1. Identify user’s needs in order to best select equipment

capacities/capabilities

2. Consider energy impact of design/procurement decisions

3. Select all system components (including IT Racks) to optimise system efficiency

4. The design process must include input from, and coordination of, all facets of the design, i.e. mechanical, electrical, comms, IT suppliers, etc.

5. Ensure design operation is documented and all staff (facilities management & IT) are trained in correct operation of system


...thank you

energy efficient data centre design 1 energy efficient data centre design presenter:tony de...

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