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The Importance of Building System Commissioning for

Energy Performance

Natascha S. CastroU.S. National Institute of Standards & TechnologyCo-Operating Agent, Annex 47 Research Project

U.S. Team Leader Annex 40natascha.castro@nist.gov

7as Jornadas de Climatização8 de Novembro de 2007

Outline

Energy efficiency in buildings• International needs & opportunities• Role of building commissioning

International collaborative research• Annex 40 /Annex 47 overview

International State of Commissioning

Conclusions & Resources

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International Interest in Energy EfficiencyIncreased understanding of the environmental impact of the

building sector• 33% of end-use energy• 30-40% GHG emissions

Source: International Panel on Climate Change SR4

AgricultureTransportBuildingsIndustrial

1971 2000 2010 2020 2030

60.0

50.0

40.0

30.0

20.0

10.0

0.0

CO

2 (G

tCO

2)

China & India (5.1 M barrels 2007 to 19 M in 2030)

Figure SPM6: Estimated sector-level mitigation potential in 2030 compared to baseline

IPCC 2007: Estimated sector-level mitigation potential in 2030 compared to baseline

International Interest in Energy Efficiency

Environmental stewardship makes business sense in the building lifecycle .• Energy costs are increasing, availability is not assured• Potential for energy savings is significant, 80% of lifecycle energy

use is in operations (heating, cooling, lighting)

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International Policy Developments

1) Low energy design in new buildings– development of very low energy buildings

• well insulated, triple glaze windows, heat recovery, efficient use of passive solar gains, low end-use energy consumption

– net zero buildings (production and consumption)

2) Energy conservation in existing buildings– optimization for end use

– energy conservation laws, EPBD

3) Emphasis on energy and the environment– LEED and Green Globes (USA, CAN), BREEAM (UK),

HQE (FR), AGBR (AUS), Passive House…etc.

History of Building Commissioning

• Need for quality assurance in building construction

• Energy efficiency retrofit programs did not achieve expected savings

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Building Commissioning

• Building Commissioning (Cx) is a quality assurance process that spans the entire design and construction process, helping ensure that the new building’s performance meets owner expectations

• Retrocommissioning (RCx) is a systematic process for improving an existing building’s performance by identifying and implementing relatively low-cost operational and maintenance improvements, helping to ensure that the building’s performance meets owner expectations

International Drivers for Commissioning

Energy benefits–10-40% energy savings and persistence–Meet national targets (e.g., Directive 2002/91/EC)

Economic benefits–Reduce change orders and callbacks for installers–Reduce service calls and complaints from occupants–Maximize savings through “as-used” optimization

Environmental benefits–Reduce carbon, NOx emissions (Kyoto Protocol)–Improved comfort, IAQ

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Example 1: RetroRetro--commissioning commissioning

RadiantRadiant System with Desiccant Wheel (USA)System with Desiccant Wheel (USA)

Maximize Use of Natural Conditioning and Maximize Use of Natural Conditioning and Thermally Neutralize the EnclosureThermally Neutralize the Enclosure

Natural ventilation/cooling with stackNatural ventilation/cooling with stack--assist, roofassist, roof--top top ventilatorsventilatorsDynamic shading, insulation, load balancingDynamic shading, insulation, load balancing

Split Thermal and Ventilation SystemsSplit Thermal and Ventilation SystemsAir & WaterAir & Water

•• Modular waterModular water--based cooling, radiant facades, radiant based cooling, radiant facades, radiant ceilings & displacement ventilationceilings & displacement ventilation

Air & AirAir & Air•• Workstation mixing boxes, Desiccant cooling (including Workstation mixing boxes, Desiccant cooling (including

heat recovery for 100% outside air)heat recovery for 100% outside air)

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RetroRetro--commissioning was carried out as part commissioning was carried out as part of the Annex 47 research project.of the Annex 47 research project.

Review of system performance, energy consumptionReview of system performance, energy consumption•• Summer performance was poorSummer performance was poor

Investigation intoInvestigation into infiltrationinfiltrationDOE 2.1 Simulation + Blower door measurements DOE 2.1 Simulation + Blower door measurements

estimation 0.1 to 0.5 ACHestimation 0.1 to 0.5 ACHActual 0.46Actual 0.46-- 1.09 ACH1.09 ACH

FindingsFindingsTested in winter showed no anomalyTested in winter showed no anomaly

Infiltration from conditioned spaceInfiltration from conditioned spaceSummer performance testing was poorSummer performance testing was poor

Infiltration from unconditioned spaceInfiltration from unconditioned spaceAir infiltration overworked cooling and Air infiltration overworked cooling and dehumidification system, energy use dehumidification system, energy use greatergreater than than conventional systemconventional system

Lesson Learned: need to commission building Lesson Learned: need to commission building systems from the design phase, particularly systems from the design phase, particularly unconventional systemsunconventional systems

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General findings in Retro-commissioning projects

• Looking at HOW systems are operating … HOW they are maintained … and most importantly WHY

• And then identifying ways to address issues so the building works well as a whole

• Catch up on maintenance, solve operating problems, ID capitol improvement needs, and training & documentation

• Retro-commissioning not necessarily energy-focused• Documentation is poor or non-existant• Symptoms can be masked (internal compensation)

– E.g., leaking cooling coil valve with reheat• Many fixes are no-cost/low-cost, short payback.

Some examples…

… frequently identifies unnecessary operating hours

– Things ON that could be OFF– Lighting sweeps not working– Round the clock operation vs. schedules

An After Hours Walk-Through …

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Examples of Findings from RCx

BIG HOLES in ducts

Poor installation: sensor placement, building envelope…

NEED: A Systematic Approach

• Best practices for identifying improper, sub-optimal operation– Tools to facilitate (improve system transparency) – Automation to reduce cost, enable more complete

testing

IEA ECBCS research projects provide the mechanism Annex 40:

Annex 47:

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The Annex was focused on HVAC systems

• To develop, validate and document tools for commissioning buildings and building services

• To produce a set of tools to facilitate commissioning internationally

The Annex conducted research in 5 areas:• The Commissioning Process• Manual Commissioning Procedures• BEMS-Assisted Commissioning Tools • Use of Models in Commissioning• Commissioning Projects

Annex 40

Process tools

• On-line glossary tool

• Standard models of commissioning plans

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1. Manual- checklists, templates for performance tests2. Automated- using building energy management system

What is a BEMS Assisted Commissioning Tool?• Monitors building control data

– invoke sequence of tests– normal operating data

• Uses artificial intelligence techniques, advanced data analysis methods and simulation technologies– Performs advanced data analyses– Predicts the behavior of components, systems and energy used– Detects faults, performs diagnosis and ongoing commissioning

• Generates detailed commissioning reports• Implemented in stand-alone tools and/or embedded in BEMS

Manual/Automated Tools

Automated Commissioning Toolsrote Markierung:

Entfeuchten (Kühler mit Nacherhitzer)

rote Markierung:Entfeuchten

(Kühler mit Nacherhitzer)

blaue Markierung:Kühlen (ohne Nacherhitzer)

blaue Markierung:Kühlen (ohne Nacherhitzer)

Tools available, both as prototypes and in field trials• Improve: performance, robustness, user friendliness, access to BEMS

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Active testing of cooling coil

0

5

10

15

20

25

30

23:30 0:00 0:30 1:00 1:30 2:00 2:30 3:00 3:30 4:00 4:30 5:00 5:30 6:00 6:30Time

Temperature

0

10

20

30

40

50

60

70

80

90

100

Control signal

Cooling coil valvecontrol signal

Return air temperature

Supply air temperatur

On/Off fan control signal

Turn on AHU, pumps and chiller and override the control of the

AHU

Closing request of valves, heat recovery and

economizer. Control signals: 0 %

Middle range operation of the cooling coil valve.

Control signal: 30 %, 60 %

Maximum opening request of the cooling coil valve.

Control signal: 100 %

Closing request of of the cooling coil valve. Control signal: 0 %

Turn off AHU, pumps and chiller. Activate automatic mode for AHU

Automatic execution of the scenario

Temperature(C)

Time of day

CITE-AHU

Visualization Tools: Carpet Plots

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Advanced Tools for Diagnostics

rote Markierung:Entfeuchten

(Kühler mit Nacherhitzer)

rote Markierung:Entfeuchten

(Kühler mit Nacherhitzer)

blaue Markierung:Kühlen (ohne Nacherhitzer)

blaue Markierung:Kühlen (ohne Nacherhitzer)

Annex 40 Results

• International view of the process• Process tools • Automated commissioning tools• System/component models• Real-building commissioning projects

– Documented lessons learned

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• Extend methods and tools to address advanced systems in low energy buildings (Integrated design )

• Automate the commissioning process (Optimization)

• Quantify and improve the costs and benefits of commissioning, persistence of savings

• Exchange information on commissioning practices and disseminate relevant information to practitioners

Annex 47

Design Construction Occupancy

Info

rmat

ion

Change of UtilizationFunctionality oriented view

Component oriented view

Possible scope of information

Real scope of information TimeBreak Break Break

OnOn--going commissioning of an airgoing commissioning of an air--conditioning system with seasonal ground conditioning system with seasonal ground

thermal storage (Japan)thermal storage (Japan)

Example 2: Optimization

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In winterIn winter cold thermal energy is stored in the ground by cold thermal energy is stored in the ground by circulating cool water processed by a cooling towercirculating cool water processed by a cooling tower. . In summerIn summer the stored energy is used as the stored energy is used as auxiliary auxiliary energy for airenergy for air--conditioning.conditioning.

AirAir--conditioning system with seasonal ground conditioning system with seasonal ground thermal storagethermal storage

Thermal storageThermal storagePolyethylene Polyethylene pipes are pipes are embedded spirally embedded spirally in in 64 64 foundation piles.foundation piles.

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Issues?Issues?Difficulty in achieving optimal operationDifficulty in achieving optimal operation

If the system is inadequately operated it will consume If the system is inadequately operated it will consume more energy than a conventional airmore energy than a conventional air--conditioning conditioning system with a common chiller. system with a common chiller. It is unknown when the circulation pump should be It is unknown when the circulation pump should be operated relative to heat storage/discharge rates.operated relative to heat storage/discharge rates.Trial of a potential operation strategy for energy Trial of a potential operation strategy for energy conservation using the real system takes one year due conservation using the real system takes one year due to the charge/discharge cycle. to the charge/discharge cycle. Trial and error approach is impracticalTrial and error approach is impractical

Use of simulation is a promising, Potential strategies can be tested rapidly.

Combined Combined SimulationSimulation

Dec.Feb.Mar.Apr.Jul.Aug.Sep.Storage Period Discharge Period

SIMLINK ANSYS (FEM)

Network model and finite element analysis performed in a MATLAB environment.

MATLAB

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Results Results of optimalof optimal operationoperation

Water flow rate : Water flow rate : 50 50 20 m3/h20 m3/hFan rotation speed of cooling tower: Fan rotation speed of cooling tower: 100% 100% 50 % 50 % Outlet water temp. set of cooling coil : Outlet water temp. set of cooling coil : 23 23 26 deg. C26 deg. C

OverallOverall systemsystem efficiencyefficiency (COP)(COP) improved by 2 to 3improved by 2 to 3 timestimes..

HeatAmount

EnergyConsumption Efficiency Heat

AmountEnergy

Consumption Efficiency

256 GJ 154 GJ

Estimated Flow rate : 50 m3/hOperating Period : 4 months

411.0 GJ 47.4 GJ 8.7

Actual Flow rate : 50 m3/hOperating Period : 2 months

213.4 GJ 27.0 GJ 7.9

Estimated Coil outlet water temp. : 23 oC 146.0 GJ 9.6 GJ 15.2 2.56

Actual Coil outlet water temp. : 23 oC 145.1 GJ 13.2 GJ 11.0 3.61

Estimated Flow rate : 30 m3/hOperating Period : 4 months

415.2 GJ 36.0 GJ 11.5

Actual Flow rate : 45m3/hOperating Period : 3 months

374.1 GJ 55.5 GJ 6.7

Estimated Coil outlet water temp. : 25 oC 195.0 GJ 15.4 GJ 12.7 3.79

Actual Coil outlet water temp. : 25 oCBypass valve was opened

205.1 GJ 8.9 GJ 23.0 3.18

EstimatedFlow rate : 30 m3/hCT fan INV : 50 %

Operating Period : 3 months279.4 GJ 21.9 GJ 12.8

ActualFlow rate : 30 m3/hCT fan INV : 50 %

Operating Period : 3 months280.3 GJ 22.8 GJ 12.3

Estimated Water flow rate : 15 m3/h 197.5 GJ 3.70 GJ 53.4 7.71

Actual Water flow rate : 15 m3/h 189.9 GJ 3.75 GJ 50.6 7.15

Storage

DischargeSystem

COP

Storage

3rd

year

Design

Operational Method

2nd

year

Discharge

Storage

1st y

ear

Storage

Discharge

Discharge

initial optimal

Year 3

Year 2

Year 1

Potential Energy Savings from Cx and RCx

• Commercial buildings >2300 m2 pay $50 billion/yr for energy in the U.S. in 2005

• Cx energy savings range: 6% - 9% – California Market Characterization Study (2000)

• RCx energy savings range: 7% - 30%– LBNL study: The Cost-Effectiveness of Commissioning New and

Existing Commercial Buildings: Lessons from 224 Buildings (2005)

??

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Worldwide recognition that buildings do not work well

Acknowledged problem in • Australia• Belgium• Canada• China, Hong Kong PRC• Czech Republic• Finland• France• Germany

• Hungary• Japan• Korea• Netherlands• Norway• Portugal• Sweden• Switzerland• Taiwan• USA• …

Status of Commissioning Implementation

Limited Commercial• Canada• China/Hong Kong • Hungary • Philippines• Singapore • Sweden• Taiwan• USA

… growing slowly

Primarily R&D• Australia• Belgium • Czech Republic • Japan• Korea• Finland• France• Germany • Netherlands• Norway• Switzerland

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Conclusions

• Industrial countries must be more ambitious to allow for economic growth in developing countries

• Commissioning has a key role to play in comprehensive quality assurance for the design, construction and operation of buildings.

• Quality assurance tools and procedures are necessary to ensure that the technical potential of building systems and components is realized in operation throughout the life of the building.

– Even more so for unconventional systems

• The buildings industry can benefit from the technology transfer from countries that commonly implement ‘advanced systems’ for low energy buildings.

• Cx still in its formative years• Grow supply and create demand…

– Improve recognition of benefits = quantifying non-energy benefits, standard cost-benefit data

– Better understand how energy decisions are made = getting the messaging right for decision makers

– Increase $ available for research and incentives = jump starting the market

– Create new tools, training, resources = improving cost affective deliver and persistence of benefits

• Set goal for R&D: Tools and persistence strategies • Continue to leverage complementary trends such as LEED and

energy-efficiency orders and directives

Conclusions (2)

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Tools and Guidelines

• Commissioning and O&M Guidelines• Web Resources

Commissioning and O&M Guidelines

-others under development Norway, Finland, France…

California Cx Guides for New and Existing Buildings

Retrocommissioning Guide for Ownerswww.peci.org/library

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Resources

• Annex 40: www.hvac-commissioning.org• Annex 47: www.ecbcs-annex47.org• BSCA:www.bsca.or.jp/english/english_top.html• Building Cx Association: www.bcxa• ASHRAE Guideline 0-2005: www.ashrae.org• CCC Sample Documents and Library: www.cacx.org• Energy Design Resources:

www.energydesignresources.com• NCBC Proceedings: www.peci.org/ncbc• Buildings & Climate Change: www.unep.fr

Continuing the Upward Trend through Collaboration

Thank you!

Questions?

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International State of Commissioning

Canada• National program on Retro-commissioning involving Gov’t

agencies and Utilities• Promoting optimization process, implementing DABO in 20

demonstration sites (including 1st early LEED buildings)

France• New certification program (HQE-idem)• Commissioning process is being implemented in operation phase• National Commissioning Guideline under development

Germany• National Guideline (EnEV 2006) sets energy efficiency

requirements for New construction and major retrofits, requires that public buildings display energy certificate

• Research program- 20 demonstration sites, results outperform energy consumption standards by 50% with no added costs

International State of Commissioning

Japan• Building Services Commissioning Association (2004)• SHASE technical committee on commissioning• 1st version of national commissioning guideline published• Energy Conservation Law mandates performance testing for major

HVAC components (April 2006)

Finland• Promoting “ToVa”, extending Energy Auditing activities• Building services technology program aims to develop methods

and tools for a “Commissioning Guidebook” and to implement in building sites

Norway• National program aims to develop and implement tools for life-

long commissioning

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International State of Commissioning

The Netherlands• Commissioning only implemented in handover, strong interest in

functional testing, working to promote whole commissioning process

• Developing tools for fault detection and diagnosis

Czech Republic, Korea, Hong Kong/ China• Research aimed at development of EMCS-based tools

USA• Commissioning penetration is less than 5% in new construction,

approximately 0.03% for existing buildings• Awareness increased though certification programs, large-owner

mandates, state and local initiatives, professional organizations, and conferences

• High demand for tools and training

Commissioning and O&M Guidelines

Functional Testing Guide www.ftguide.org