dc2013_workshop-efficiency-in-the-datacentre by saad alshammari

Data Center Efficiency Workshop Jack McArdle Managing Director Kirlaur Ltd

Introduction Jack McArdle Kirlaur Ltd Independent Data Centre Consultancy – – – – – – –

Efficiency Consulting SMART Metering Design and Build Management ROI Engineering UPS Design and Management Data Center Project Management Migration Planning Consultants

Introduction Clients – – – – – –

Axcess Financial Ltd Gamma Telecom Ltd ScoLocate brightsolid Pulsant Ltd Gamma Telecom

Partnerships Trendpoint Inc •

•

Enersure metering, Branch Monitoring • UK Distributor (Trendpoint UK Ltd) • European Distributor (Trendpoint Europe Ltd) SMART Metering

Aims of Workshop • Discuss what efficiency actually is • Discuss how we determine how efficient our DC is – Metrics and measurements

• Discuss how we monitor DC efficiency – Green Grid, Codes of Conduct etc

• Recognising the need for improvements – Business Drivers – Monitor, Plan, Do, Manage, Improve cycle

• Discuss where the inefficiencies exist • Finding the losses

• Discuss how we improve our DC – Making the gains • Today, Tomorrow, Ongoing

What is Efficiency? Efficiency in general describes the extent to which time, effort or cost is well used for the intended task or purpose. Are Data Centers efficient? • •

If all the Data Centres in the world were a country they would rank somewhere between Spain and Italy in power consumption (DCD Intelligence 2013) Approximately 38Gw of power used by Data Centers worldwide – 63% increase in the last 12 months (Data Centre Dynamics)

Most of this energy is wasted!

•Converted to heat and dumped into the environment as waste •Creating carbon (power generation) •Costing millions in cash

Difficult to quantify –No end product

What is Efficiency? What actually is Efficiency? Will it save money? Yes it will help reduce Operating Costs! Will it save the planet? It wonâ&#x20AC;&#x2122;t do any harm! Will it save resources? It will help! Is it working smarter? Best practice always helps! Good discipline in the industry

It is all of these things!, but.... How do you quantify it? Jack McArdle ÂŠ2013

Metrics and Measurements

Jack McArdle ÂŠ2013

Metrics and Measurements If you don’t know what is happening in your Data Center, you can’t change or improve it.

There must be some kind of metric in place to allow value-based, knowledgeable decisions to be made. You need to measure power to manage costs or charge clients.

Metrics You can’t manage what you can’t measure! There are many metrics available for Data Center reporting. The following slides will cover each type and discuss the relative merits of each. The Green Grid™ has defined the xUE family of metrics to complement each other. • • • • • •

PUE/DCiE: Power Usage Effectiveness/Data Centre Infrastructure Efficiency pPUE : partial Usage Effectiveness CUE: Carbon Usage Efficiency WUE: Water Usage Effectiveness DCcE: Data Center Compute Efficiency ERE: Energy Re-Use Efficiency

PUE, DCiE and pPUE • Originally developed by The Green Grid™ it has received a lot of industry attention. • “The Green Grid™ notes that many published PUE or DCiE numbers are not measurements but are estimated by engineers for hypothetical conditions, such as for Data Centers under construction, or for IT loads other than the actual IT load” • Now a ‘marketing term’ • Typically addresses the facilities side of the equation. • Is a continual process, not a goal. • There is an assumption that ‘lower PUE’s are better’.

xUE Metrics

Jack McArdle ÂŠ2013

xUE Metrics – Power Usage Effectiveness PUE, part of the new ‘Sustainability’ metric is defined as the ratio of Total Facility Energy to IT Equipment Energy PUE =

Total Facility Energy IT Equipment Energy

For a Data Centre having an incoming supply(Total Facility Energy) of 800kWatts and an IT Equipment Energy(measured at the UPS) of 500kWatts then: PUE =

800kW 500Kw

= 1.6

xUE Metrics The Green grid, has recently issued the xUE Metrics white paper.

These metrics are designed to help IT and Data Center organisations better understand and improve both the sustainability and energy efficiency of their existing Data Centers, as well aiding the operator in making informed decisions on the deployment of new facilities. It was recognised that Data Center power footprint, energy usage and carbon emissions were affecting companies decisions on growth, building locations and outsource strategies Jack McArdle ÂŠ2013

Data Centre Infrastructure Efficiency - DCiE DCiE is an older metric, used in reports to quantify the efficiency of the use of energy, expressed as a percentage. It is found by taking the reciprocal of the PUE figure and multiplying by 100

DCiE =

IT Equipment Energy X 100 Total Facility Energy

From the previous Data Center example:

DCiE = 500 800

X 100

DCiE = 62.5%

Jack McArdle ÂŠ2013

This reports that the Data Center is 62.5% efficient on its energy use

xUE Metrics - Carbon Usage Effectiveness CUE is another new ‘Sustainability Metric’ defined by The Green Grid™. Like PUE, CUE uses total IT energy as the denominator. Once you have determined the PUE the value is used for the new metric. CUE as a metric has a dimension while PUE has not. CUE has an ideal value of 0.0, but like PUE has no upper limit. The metric for carbon usage in the data center is defined at a high level as: CUE =

Total CO2 emissions caused by Total DC Energy IT Equipment Energy

Total DC Energy is the same value as the numerator used in the PUE metric The units of CUE is kg of CO2 per kilowatt hour (kwh)

xUE Metrics - Carbon Usage Effectiveness As an alternative method of calculation, you can multiply the Carbon Emission Factor (CEF) by the PUE CUE = CEF x PUE

For Kuwait, the CEF is 0.637 kgCo2/kWh CUE = CEF x PUE From our previous example, CUE = 0.637 x 1.6 where the Data Center had a PUE CUE = 1.0192kgCO2/kWh of 1.6, in Kuwait the CUE would be: On an annual basis, the DC with 800kW energy use would emit (or cause to be emitted) 8760(hrs/a) x 800(kW) x 1.0192(CEF) = 7,142,553.6 kgCo2 annually Note that the additional figures from gas-oil caused by running a generator should be added Jack McArdle ÂŠ2013

xUE Metrics - Water Usage Effectiveness WUE is a relatively new ‘Sustainability Metric’ defined by The Green Grid™. The metric for water usage in the data center is defined at a high level as:

WUE =

Annual Water Usage IT Equipment Energy

The units of WUE are litres/kilowatt-hour (L/kWh). In its entirety, it is a very complex metric which may, or may not be adopted by the Data centre industry.

With WUE, the issue of a “source based” versus “site-based” metric must be considered. The main issue is that water use or changes to a site’s water use strategy generally affects other site use parameters and also can affect the supply chain for different utilities Jack McArdle ©2013

xUE Metrics - Water Usage Effectiveness • A reduction in water use on-site can be accomplished a number of ways. The most attractive way is simply to employ optimal design, then increase operational efficiencies and tune the existing systems. • Re-commissioning a facility can accomplish this. The industry is replete with horror stories of data centers where one computer room air conditioning (CRAC) unit is dehumidifying while another is humidifying at the same time, wasting both water and energy. • In addition, many data centers have yet to take advantage of the ASHRAE 2011 extended environmental envelope where recommended minimum humidity levels have been reduced to 5.5°C (42°F) dew point. Jack McArdle ©2013

PUE Levels (Green Grid) Level 1 Basic

Level 2 Intermediate

The IT load is measured at the output of the UPS equipment and can be read from the UPS front panel, through a meter on the UPS output, or, in cases of multiple UPS modules, through a single meter on the common UPS output bus. The incoming energy is measured from the utility service entrance that feeds all of the electrical and mechanical equipment used to power, cool, and condition the data center

The IT load is measured at the output of the PDUs and can b typically be read from the PDU front panel or through a meter on the secondary of the PDU transformer. Individual branch circuit measurement is also acceptable for Level 2. Intermediate monitoring requires, at a minimum, the collection of power measurements once a day.

Level 3 Advanced The IT load is measured at each individual piece of IT equipment within the data center, either by metered rack PDUs (i.e., plug strips) that monitor at the strip or receptacle level or by the IT device itself. Note that non-IT loads must be excluded from these measurements. Advanced monitoring requires, at a minimum, the collection of power measurements once every 15 minutes or less; for energy measurements, that frequency is recommended. Level 3 measurements should not require human activity to gather and record data.

Jack McArdle ÂŠ2013

Three Tier Approach to PUE PUE is still the most widely used (and abused) Metric in the Data Center industry today. However, used and managed properly it is a simple, but very useful reporting measurement in the fight to gain efficiency wins. It should be viewed as an organic process with constant monitoring attached. The table below lays out the Green Gridâ&#x201E;˘ roadmap for PUE development Level 1 (L1) Basic

Level 2 (L2) Intermediate

Level 3 (L3) Advanced

IT Equipment Energy

UPS Outputs

PDU Outputs

IT Equipment Input

Total Facility energy

Utility Inputs

Measurement interval

Monthly/Weekly

Daily/Hourly

Continuous <15 minutes

Jack McArdle ÂŠ2013

Notes on Calculating PUE Partial PUE, or pPUE is useful if the Data Center shares its location with other, non – DC related activities. The calculation remains the same for both and DCiE can be derived none-theless. It is not always the case that reducing power elements within the facility will have a positive effect on the PUE If a DC has an incoming supply of 1MWatt and an IT load of 500kWatt, then the PUE = 2.0. (1/0.5) If after a virtualisation or ‘ghost server’ exercise, the IT load becomes 250kWatts, then the PUE will actually rise to 4.0. (1/0.25)

Notes on Calculating PUE If the approach to the project was the other way round, i.e. lets remove some redundant HVAC if your installation is scalable enough to do so, then the gains will be made. If a DC with an incoming supply of 1MWatt and an IT load of 500kWatt and PUE = 2. then removes, for instance 4 x HVAC units that it doesn’t actually need and saves 200kWatts of Facility load then the PUE will become 1.6. (800/500). The aforementioned rationalisation exercise will then raise the PUE to 3.2 (800/250). As you can see, it is by no means a perfect metric, however it is by far the most popular, and a very good starting point.

Partial PUE Summary • PUE can be used to compare data center designs • Often PUE's are presented that do not take into account all of the infrastructure components in order to highlight one particular portion of a data center • “Container only” PUE • “Cooling system” PUE • “Power delivery” PUE • These comparisons have value, but are not truly PUE – Partial PUE provides a formal language for this – Partial PUE is abbreviated “pPUE Jack McArdle ©2013

Partial PUE Summary PUE = Total Facility Energy divided by the IT Equipment Energy

This takes into account energy use within a facility. Partial PUE is for energy use within a boundary

pPUE = Total Energy within a boundary divided by the IT Equipment Energy within that boundary

Jack McArdle ÂŠ2013

pPUE Summary

PUE Varies by Month, and Load PUE by Month and Load 12.00 11.00 10.00

100%

9.00

90%

8.00

80%

7.00

70%

6.00

60%

5.00

50%

40%

4.00

30%

3.00

20%

2.00

10%

1.00 Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Energy Reuse Efficiency (ERE) • I am re-using the waste heat from my Data Center so my PUE is 0.7! • Not Quite

• While re-using excess energy from the data center can be a good thing to do, it should not be rolled into PUE • The definition of PUE does not allow this. • There is a metric to do this! ERE Jack McArdle ©2013

Energy Reuse Efficiency (ERE) PUE =

Total Energy IT Energy

ERE =

Total Energy – Reused Energy IT Energy

ERE =

Cooling + Power + Lighting + Security = IT

Cooling + Power + Lighting + Security - Reused IT

You can also define an Energy Reuse Factor (ERF) by: ERF =

Reuse Energy Total Energy

1 ≤ PUE ≥ ∞ 1 ≤ ERE ≥∞ 0 ≤ ERF ≥ 1

DCcE – Unused Servers ~15% of servers powered on but not being used CPU utilization doesn’t tell the whole story Virtualization doesn’t cure the problem – it can make it worse Removing unused servers will increase data center efficiency Reduce power for physical servers Reduce resource usage for virtual servers Servers are procured to provide a primary service. If they are no longer providing this service then they are no longer needed and should be decommissioned or repurposed. Useful work <> CPU utilization Secondary & tertiary services can cause utilization Virus scanning Disk indexing / defragmentation Backup

DCcE – Determining Primary Service Usage Tracking primary services resource utilization is impractical – too many different primary service apps

Tracking secondary & tertiary services is easier – typically a well known small set of applications Primary service work = All work – secondary & tertiary work True for CPU & I/O

Some applications do not lend themselves to measurement like this – e.g. terminal services →Track incoming network sessions for ‘useful’ processes → Track interactive logons – always assumed to be useful

DCcE - Calculating Primary Service Usage Over a time period..... If

All CPU minus secondary & tertiary CPU > noise threshold Or All I/O minus secondary & tertiary I/O > noise threshold Or There have been incoming network sessions for primary services Or There has been an interactive logon Then Server was being useful Else → → → Server was not being useful Jack McArdle ©2013

Server Compute Efficiency - ScE ScE is the proportion of samples that the server is providing primary services over time (as a percentage) Any server with an ScE of 0% over a prolonged period is not being used and can be decommissioned or repurposed

Any servers having a low ScE are worth investigation → they may be candidates for virtualization

Data Center compute Efficiency (DCcE) aggregates ScE across all servers in the data center and provides a benchmark against which to improve (like PUE) DCcE is NOT a productivity metric – it does not measure how MUCH work is done, just the proportion of work that is useful DCcE CANNOT and SHOULD NOT be compared between data centers due to the subjective determination of secondary and tertiary processes Jack McArdle ©2013

Metrics and Measurements Summary

Jack McArdle ÂŠ2013

Aims of Workshop PUE: Power Usage Effectiveness Aim to improve Easy to Quantify pPUE: Partial Power Usage Effectiveness CUE: Carbon Usage Effectiveness WUE: Water Usage Effectiveness All part of the xUE group of Metrics ERE: Energy Reuse Efficiency DCcE: Data Center Compute Efficiency DCiE: Data Center Infrastructure Efficiency Useful Reporting Tool Jack McArdle ÂŠ2013

Efficiency Improvements Drivers for Efficiency Finding the Losses

Jack McArdle ÂŠ2013

Drivers for Efficiency Why bother ? New Build Costs Proper planning, to a target PUE will allow value based decisions to be made in regards of scalability. CapEx can be spread across a longer time by only buying infrastructure components as they are required.

Operating Cost Proper Efficiency Management will result in significant reduction in energy costs across the DC estate.

Jack McArdle ÂŠ2013

Drivers for Efficiency • ASHRAE recently changed the envelope for operating temperatures and humidity levels. • Allowable Range now 20% RH to 80% RH

Drivers for Efficiency • Changing the ‘On Air’ set-point on the HVAC by 1oC can reduce the operating cost by up to 4% • Controlling the actions of humidifiers can save up to 20% of the operating cost. – Most traditional humidifiers are large ‘electric kettles’ – Do you need to have them boiling all day

Quick Case Study European Data Centre GEA Denco Ambicool Units (n+1)- Before 18o C ‘on-air’ 23oC ‘return air’ RH set at 50% ±5% 30 day cost for 18 units in 6 vaults: 518,400kWh - £ 4,924.80

Finding the Losses • In legacy systems there are some losses that you struggle to win back: • Working on the principle that you get ‘nothing for nothing’, our job as Data Center Managers is to ensure that we can get enough free bits as possible. • Starting on a new build allows traditional thinking to change. – Build as you need – Scalability – Run the Data Center Hot – Follow the ASRAE Guidelines

• Only add humidity as required • Speculate to Accumulate

Electrical Losses • Transformer – 20% Loss

• Traditional UPS – 20% Loss

• Generator – 20% Loss

• Lighting – Always On – 10 to 20% Overhead

Mechanical Losses • HVAC – Type Dependant • Up to 40% Overhead (Can be as high as 100%)

– On Air Set-point • 2 to 4% of cost for every 1oC rise

– Airflow • Obstructions – Fans Run Harder = 5% – Hotspots

– Air Mixing • Hot and cold air mixing on return

IT Losses • Ghost Servers – Where are they – What do they do

• Replicated Servers – Where are they

• Test bed Servers – Are we finished with them

Finding the Losses Power Consumption with PUE = 1.6

5 kW 15 kW

1MVA

240 kW

Ventilation – Fresh Air

Lighting & small power

Cooling fans, pumps & compressors

IT 500 kW

35 kW

IT terminal load Distribution & conversion losses

3 kW Security, BMS 2 kW Communications

Total 800 kW

Finding the Losses

Jack McArdle ÂŠ2013

Planning for Efficiency

Jack McArdle ÂŠ2013

Planning for Efficiency •Start as a Project •Make it a Process

} Best Practice • Investigate

Monitor

Improve

Record

• Speculate

Monitor

Change

• Plan

Monitor

Record

Review

Change • Savings

Planning for Efficiency Initial Steps • Electrical Systems – – – –

Lighting UPS Configurations UPS Redundancy Power Factor Correction

Save 10% Overhead Cost Loading Designs Scalability Save Utility charges

• HVAC – – – –

Air-Flow Air Mixing and Hotspots Redundancy Configuration Keep Filters Clean

Keep it Clear and Free Separate and Blank Balanced v N+1

Planning for Efficiency Initial Steps • IT Systems – Ghost Servers • Find them and remove them

– Replicated Servers • Find them and remove them

– Test/Development Servers • Are they still used

– Technology Refresh • Purchase carefully

– Density Mixing • Separate High and Low Power/Heat Output devices

Planning for Efficiency - Recording Phase 1a Plan • Meter and Record – Utility Supply Meter – High Level Electrical • • • •

Main Switchboards Critical Distribution Boards Mechanical Distribution Boards Security/Environmental Distribution Boards

– High Level Environmental • Room Temperatures – At Least 3 readings

• Room Humidity – At least 3 readings

Planning for Efficiency Phase 1b Plan • Meter and Record – Sub Level Electrical • Critical Distribution Board Outputs – Rack Level

• Mechanical Distribution Boards – Per HVAC Unit

• Security/Environmental Distribution Boards – Single Board Meter will suffice

– Granular Environmental • Aisle temperatures – Supply and Return

• Room Humidity – Supply and return averaged

Planning for Efficiency – Branch Metering • Amperage -Knowing exact amperage eliminates tripped breakers • Voltage – See power spikes and sags and head off trouble • Power Factor – Track the hidden penalty in your power bill • kW – See the actual wattage of heat generated by each circuit • kWh – Track energy by end user and groups • Green House Gases – Track carbon footprint by user and department

Planning for Efficiency – Branch Metering

Planning for Efficiency Phase 2 Plan • Containment Systems Optimisation of Airflow All Spaces should be blanked Requires intelligent management Allows for a ΔT of 10oC – 15oC Thermal Imaging before and after

Planning for Efficiency - Airflow Optimisation

Optimisation of Airflow in the Data Center • Eliminating Bypass Airflow • Preventing Recirculation of Hot Air • Separation of Hot and Cold Air • Keeping side cooled Network Equipment from overheating • Environmental Monitoring

Planning for Efficiency â&#x20AC;&#x201C; Separate Hot and cold Air Typical high end Data Centres have 2.5x their required cooling capacity. But they often use all the available cooling because of cooling inefficiencies. The key to regaining this lost capacity is to reduce as much as possible the thermal mixing of hot exhaust air from servers with expensive cooled air from the cooling units.

Jack McArdle ÂŠ2013

MIXING = INEFFICIENCY

Planning for Efficiency Eliminate Bypass Airflow Prevent Bypass Airflow What is Bypass Airflow? Conditioned air that is not pulled through air intakes of IT equipment

What causes Bypass Airflow? Air escaping through holes/openings around the perimeter of the data hall. Air escaping through racks not using blanking panels Air escaping around the side and tops of racks

Jack McArdle ÂŠ2013

Planning for Efficiency – Impact of Bypass Airflow • Many Data Centres have 50% to 80% bypass airflow. • LESS than 10% is desired. • Bypass airflow has three unwanted effects: • Hot spots in critical IT infrastructure – Low raised-floor static pressure results in cool air not reaching critical equipment

• Cooling unit inefficiency – Air is cooled that has never done its job – cool IT equipment. It continues to circulate and be cooled without being effective therefore the cooling units appear not to work at their rated capacity levels.

Planning for Efficiency – Recapture Bypass Airflow • How can Bypass Airflow be prevented? – Seal all openings in the raised floor with Control Seal type equipment – Save up to 60% in Energy Costs – Prevent downtime caused by hotspots – Increase static pressure – Each unsealed hole equates to ½ KW of wasted energy

• Features – Aluminium frame available in custom sizes – 2 layer brush with additional membrane to stop escaping air – Dissipates static charges in cables – Integrated and low profile surface mount (only 1.5cm) versions Jack McArdle ©2013

Planning for Efficiency – Prevent Recirculation

• What is recirculation of hot air? – Caused when hot air from the back of the rack returns to the air intake on the front of the rack instead of returning to the Cooling units

• What causes hot air recirculation? – Open space in racks (not using blanking panels) – Hot air wrapping around the end or top of a rack to the front – Racks not aligned in hot and cold aisles

Planning for Efficiency – Blanking Panels • •

How can Recirculation of hot air be prevented? Blanking panels

•

The physical barrier keeps cold air at the front of the cabinet separated from the hot air at the back. This prevents hot spots and helps prevent hardware failures or downtime caused by overheating. According to Gartner, when blanking panels are deployed throughout the data centre, the temperature can be decreased up to 4°C – which is equivalent to an energy saving of 20%.

Planning for Efficiency – Blanking Panels Thermal Imaging - Before and After

Five minutes after installation of blanking panels without gaps, IT equipment intake temperatures, at the bottom of the cabinet had dropped approximately 8ºC (15 ºF).

Planning for Efficiency Side Baffles deployed vertically on the side of 19 Racks - Before and After Images

No M1 M2 M3 M4

Temp.[°C] 27.8 27.4 26.1 26.0

Emiss. 0.95 0.95 0.95 0.95

Refl.Temp.[°C] 6.0 6.0 6.0 6.0

No M1 M2 M3 M4

Temp. [°C] 16.9 17.8 17.7 18.6

Emiss. 0.95 0.95 0.95 0.95

Refl.Temp.[°C] 6.0 6.0 6.0 6.0

Planning for Efficiency – Separation of Hot and Cold

Planning for Efficiency

Jack McArdle ÂŠ2013

Planning for Efficiency

Jack McArdle ÂŠ2013

Efficiency versus Resilience

n+1 n+n

2n+1

How much resilience do you need? Original T4 design can only be 33% utilised. Not very efficient. Diesel Rotary UPS 19% more efficient than UPS + Generator Scalable UPS design allows for n+1 modules 5 x 40kvA modules = 160kVA + 40kVA 3 x 80kVA devices = 160kVA = 80kVA Running 3 machines instead of 1

Jack McArdle ÂŠ2013

Efficiency versus Resilience â&#x20AC;&#x201C; UPS Considerations A UPS is rarely used at full rated load, in particular in installations using redundant UPSs to provide continuous protection even when one of the units fails or is being serviced. The load is therefore generally lower than 100% of the rated capacity. Given that certain losses are practically constant, the efficiency will decrease with load level. It is therefore important to ask the UPS manufacturer for efficiency curves at typical load levels, often 25 to 50% of the full rated load. Efficiency

100.00% 90.00% 80.00%

It is also important to avoid over sizing the UPS with normal power not too far from the load level, as at low load the efficiency decreases. An optimum efficiency curve should have the following shape:

70.00% 60.00%

Transformerless Transformer Based

50.00% 40.00% 30.00%

20.00% 10.00% 0.00% 0.00% Jack McArdle ÂŠ2013

Load 25.00%

50.00%

75.00%

100.00%

Efficiency versus Resilience Diesel Rotary UPS (DRUPS)

Jack McArdle ÂŠ2013

Efficiency versus Resilience – HVAC Considerations

• • • •

Utilise Free Air Cooling Utilise EC Fans (Direct Drive) Utilise Water Based Systems Evaporative, Adiabatic, CW Chillers – 90% more efficient than traditional – 35kW cooling for 1.5kW Electricity

• Run Data Center Hotter – New ASHREA Guidelines

• Use Containment

HVAC Considerations – Evaporative Cooling

HVAC Considerations – Adiabatic Cooling

ASHRAE www.ashrae.org ASHRAE, founded in 1894, is a building technology society with more than 54,000 members worldwide. The Society and its members focus on building systems, energy efficiency, indoor air quality, refrigeration and sustainability within the industry. Through research, standards writing, publishing and continuing education, ASHRAE shapes tomorrow’s built environment today. ASHRAE was formed as the American Society of Heating, Refrigerating and Air-Conditioning Engineers by the merger in 1959 of American Society of Heating and Air-Conditioning Engineers (ASHAE) founded in 1894 and The American Society of Refrigerating Engineers (ASRE) founded in 1904. • Mission: To advance the arts and sciences of heating, ventilating, air conditioning and refrigerating to serve humanity and promote a sustainable world. • Vision ASHRAE will be the global leader, the foremost source of technical and educational information, and the primary provider of opportunity for professional growth in the arts and sciences of heating, ventilating, air conditioning and refrigerating. Jack McArdle ©2013

ASHRAE

Outdoor air temp reduced from 35°C to 21°C by simply adding moisture

Room

21°C

Kuwait Climate Altitude; 55 m (180 ft). The average temperature in Kuwait City is 25.8 °C (79 °F). The range of average monthly temperatures is 24 °C. The warmest average max/ high temperature is 45 °C (113 °F) in July. The coolest average min/ low temperature is 8 °C (46 °F) in January. Kuwait City receives on average 96 mm (3.8 in) of precipitation annually or 8 mm (0.3 in) each month. On balance there are 18 days annually on which greater than 0.1 mm (0.004 in) of precipitation (rain, sleet, snow or hail) occurs or 2 days on an average month. Mean relative humidity for an average year is recorded as 55.3% and on a monthly basis it ranges from 41% in July to 65% in December. Hours of sunshine range between 7.0 hours per day in December and 11.0 hours per day in August. Jack McArdle ©2013

Kuwait Climate

Jack McArdle ÂŠ2013

PUE Outcomes • • • •

On Average, typical DC is ~ 2.0 High range > 2.75 Low range < 1.5 What happens to PUE if we raise the temperature? Cooling load goes down, PUE goes down • What happens to PUE if we shut 10% of servers that are deemed ghost servers? IT load goes down, PUE goes up • What happens to PUE if we also throttle the cooling to meet the new lower IT loads? IT load goes down, Cooling load goes down, PUE could remain the same PUE is useful but may not be the ‘end all’. Jack McArdle ©2013

Real World Example • Standard data centre with the following data: • • •

174 Racks x 6 kW/Rack, total 42 kW Thermal Load, limited to 2 kW/m Cooling is using the sub floor with perforated tiles Inlet temperature: 18oC , server inlet temperature: 22oC

PUE = 1.8 • Actions to reduce PUE – – – –

Close all unneeded openings in the floor: PUE = 1.8 Reduction of rotation speed of CRAC to minimum: PUE -> 1.55 Reduction of aerodynamic resistance in subfloor: PUE -> 1.48 Increase of cold water temperature in chillers from 8 to 14 deg: PUE -> 1.43 – Increase of Inlet temperature according to ASHRAE: PUE -> 1.43 – Double the IT load

Efficiency Low PUE: Is that ‘sustainable’ engineering? Cooling efficiency Site selection, latitude and local climate (water-usage a limiting factor?) Rigorous air-management in the room (limited by delta=T?) High server inlet temperature (avoiding fan ramp-up, 27°C) Minimum humidification and de-hum (if any?) Free-cooling coils for when the external ambient is cool If possible avoid compressor operation altogether Power efficiency Avoid high levels of redundancy and low partial loads in general Design redundancy to always run at >60% load Adopt high-efficiency transformer-less UPS where efficiency is c96% at 60% load Adopt eco-mode UPS where efficiency is 99% for >95% of the year Apply high efficiency lighting (scraping the barrel at 1%) Best practice gets us to a PUE of 1.2 Extreme data-centre ‘engineering’ gets us down to 1.07 Jack McArdle ©2013

Efficiency Can data centres be ‘sustainable’ or ‘green? Not in isolation!

Data centres are the factories of the digital age. They convert power into digital services – its impossible to calculate the efficiency’ as there is no definition of ‘work done’. All the energy is treated as waste and, in almost every case, is dumped into the local environment Only if the application of the data centre can be shown to be an enabler of a low-carbon process. Neither are they ‘green’, unless … The load is a low-carbon solution They have minimised consumption by best-in-class hardware They have reduced PUE to the minimum They source power from renewable (or low-carbon?) sources? They re-use waste heat… Is a ‘parallel computing’ model ‘efficient’? If you build two ultra-low PUE facilities (close to PUE=1) to push redundancy and availability into the hardware-software layer then your peak overall PUE will be >2 Jack McArdle ©2013

Links and Credits

The Green Grid: ASHRAE: Trendpoint: Daxten: EcoCool:

Jack McArdle ÂŠ2013

http://www.thegreengrid.org/ https://www.ashrae.org/ http://www.trendpoint.com/ http://www.daxten.co.uk/ http://www.ecocooling.co.uk/

Thank You