ECOLI BR I U M • MARCH 201444

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Council House 2 (CH2) in reviewMatthew Hoogland, M.AIRAH, Exergy Australia; and Dr Paul Bannister, M.AIRAH, Exergy Australia

ABSTRACTCouncil House 2 (CH2) is the City of Melbourne’s flagship building for sustainability. The building showcases a number of innovative technologies and has attracted recognition with numerous environmental awards. But how does the building actually perform and what lessons does it have for the broader industry? The City of Melbourne was asking these questions when they invited Exergy to conduct a review of the building’s energy efficiency performance in July 2012.

Exergy’s review focused on the operation of the building’s various systems, including passive chilled beam, tri-generation, thermal storage phase-change material, shower towers and more. Key issues identified mainly pertained to the HVAC commissioning and control strategies applied to these systems not only in isoaltion, but in the complex web in which they come together.

The City of Melbourne is now in the process of implementating the first stage of measures with calculated potential to reduce energy consumption by 25%. Crucial to the success of this project will be a staged process of implementation and measurement to determine how best the building’s systems can complement each other in various modes of operation.

INTRODUCTIONOfficially opened in August 2006, CH2 was Australia’s first 6 star Green Star – Design building, and showcases a number of sustainable building features. The building was designed to set new standards for low energy and high occupant comfort, bringing together a range of innovative technologies not only for the benefit of those to work in it, but also to serve as a sounding board for the broader industry.

But how does the building actually perform? With doubt that the building was achieving its ambitious targets, the City of Melbourne invited Exergy to undertake a review of the building’s energy efficiency performance in July 2012, providing an opportunity to review the performance of the innovative and experimental design features of the building.

The aims of the project were to:

• Quantify the existing performance of the building against NABERS1 Energy benchmarks

• Identify issues impeding energy efficiency performance

• Detail measures to improve the NABERS Energy rating

• Identify lessons that can be learnt from CH2.

The review was based on the findings of a whole building level 2 energy audit conducted by Dr Paul Bannister, M.AIRAH; Matthew Hoogland, M.AIRAH; and Ben Carmichael of Exergy Australia as per the requirements of AS/NZS 3598:2000.

Note that the scope of the review was predominantly targeted at identifying energy efficiency measures to improve the NABERS Energy performance of the building. We acknowledge that there are numerous features of interest within the building. However, in general, our investigation only went as far as that required to improve the efficiency of the core systems that the energy audit revealed to be making a significant impact on the building’s consumption. As such, detailed investigation of the peripheral features of the building such as renewable power sources and automated shading systems were not covered. We also note that water efficiency and indoor environment quality were not included in the scope of the review.

BUILDING FEATURESThe features of CH2 that were intended to contribute to high-level energy performance are listed below. Note that we have divided the features according to the significance with which we observed them having to the building’s current performance:

• Core features:

– Passive chilled beam cooling

– Tri-generation

– Hydronic radiant heating

– Extensive heat transfer and recovery between water loops

– Phase-change material tanks for thermal storage.

• Peripheral features:

– Building integrated wind power

– Solar PV and domestic hot water

– Shower towers

– Electronically actuated windows and shading

– Daylight harvesting.

At the time of CH2’s construction most of these technologies were far from common within Australia’s commercial building industry. And while chilled beam technology and tri-generation systems have since become more widespread, features such as the shower towers and phase-change storage tanks are still relatively uncommon among Australia’s commercial building stock.

Of the building’s array of technologies, arguably most technically significant is the extensive potential for heat transfer between the seven distinct water loops. A water schematic of the site’s servicing is presented in Figure 2. Among others, heat exchangers can be observed between the domestic hot water system and the primary heating water system, the primary heating water system and the primary condenser water system, the primary condenser water system and the supplementary condenser water system, and the supplementary condenser water system and the primary heating water system. Although none of these processes in isolation are particularly unusual, their summation equates to a system of unusual potential and complexity.

45MARCH 2014 • ECOLI B R I U M

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The complexity of CH2’s design, coupled with the industry’s general lack of familiarity with its features has proven to be one of the key challenges for the building’s operation.

Figure 1: CH2 west facing facade (from Swanston St).

Table 1: Heat exchanger (HEX) legend corresponding to Figure 2.

H

H

H

H

C C

C C

CC

C

C

C

C

H

H HCC

C

C

C C

C

C

H

Primary CHW loop

Secondary CHW loop

HHW loop

Shower tower loop

Primary CDW loop

Chilled beam loop

Tenant CDW loop

Heat flow

Cool flow

Boilers

AHUs

Showertowers

L1-9chilled beams

L1-9heating

convectors

L1-9CDW

DHWHEX

PCMtanks

HEX 5

HEX 6

HEX 3

HEX 1

HEX 2

HEX 4

Retail PACs

HEX 7

HEX 8

Microturbineheat recovery

Absorptionchiller

Cooling towers

Screwchillers

Figure 2: Simplified water schematic of HVAC services for CH2, demonstrating the diverse array of water loops and the heat transfer potential between them. Note that each line represents a flow and return path. See HEX legend in Table 1.

Unit Description

HEX-1 HEXtotransfercoolthfromtheprimaryCHWtosecondaryCHW

HEX-2HEXfortransferbetweenthecoolingtowersandthesupplementaryCDWsystem

HEX-3 HEXforheatrecoveryfromtheprimaryCDWreturntoairsideheating

HEX-4HEXforheatinjectionintothesupplementaryCDWsystem(forreverse-cyclePACs)

HEX-5HEXfortransferofcoolthfromtheshowertowerstothechilledbeamnetwork

HEX-6HEXfortransferofcoolthtopre-coolthesecondaryCHWreturnafteritspaththroughHEX-7and/orHEX-8

HEX-7

HEXfortransferofcoolthfromthesecondaryCHWsystemtoeitherofthechilledbeamnetworkdirectlyorviathePCMtanks(paralleltoHEX-8)

HEX-8

HEXfortransferofcoolthfromthesecondaryCHWsystemtoeitherofthechilledbeamnetworkdirectlyorviathePCMtanks(paralleltoHEX-7)

ECOLI BR I U M • MARCH 201446

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CURRENT ENERGY PERFORMANCEThe actual energy performance of CH2 does not currently meet the high standard of its design. Our analysis revealed the whole building NABERS Energy performance of the building to be 4.08 stars. With the aid of data obtained from the floor-by-floor sub-metering system we were able to drill down to investigate the weighting of the base building and tenancy on the whole building performance. Our analysis found the base building to be performing at 3.24 stars NABERS. With several major property owners in Australia now reporting average portfolio ratings of 4.5 stars or higher, this is well below the current industry standard for good performance2. At 3.24 stars, the emissions attributable to CH2’s base building services are 68% greater than what they would be if the base building was performing at 4.5 stars.

ENERGY CONSUMPTION ANALYSISInterval data was obtained for the office building’s sole electrical utility meter. The analysis revealed unusual variation in the base load over weekdays and seasons, as presented in Figure 3. With minimal occupation of the building outside of business hours, these observations were tell-tale signs that there may have been frequent HVAC operation occuring outside of the operational hours of the building.

Site inspections were conducted over a course of several months and at various times of the day and night to observe the building in its different modes of operation. The end-use breakdown is presented in Figure 4 as constructed according to the findings of the site inspections. A Sankey flow diagram (Figure 5) was

also produced to help illustrate the diversity of energy sources and complementary systems within the building.

It is noted that the sub-metering system could not significantly inform the breakdown of base building services due to inadequate coverage and poor data quality from some meters.

KEY ISSUESThe key issues preventing CH2 from realising its potential were found to be in the strategies and commissioning of its HVAC controls. Widespread opportunities for optimising control were observed and could broadly be categorised into three groups:

• Priority of cooling modes. One way in which CH2 is unlike most buildings is that it has several different ways of generating cooling to provide to the floors. The source of cooling can either be via absoprtion chiller heat recovery

Whole building NABERS 

rating

Estimated base 

building NABERS 

rating

Estimated tenancy NABERS 

rating

Date range

1/7/11to30/6/12

1/7/11to30/6/12

1/7/11to30/6/12

Electricity (kWh) 971,270 571,292 399,978

Gas (MJ) 5,133,122 5,133,122 0

Diesel (Litres) 0 0 0

Hours of occupancy 49.2 49.2 49.2

No. of computers n/a n/a 454

NABERS rating (decimal)

4.08 3.24 5.43

NABERS star rating 4.0stars 3.0stars 5.0stars

Table 2: NABERS Energy performance parameters for July 2011 to June 2012.

0

50

100

150

200

250

kW

MonTue

WedThu

FriSat

Sun

0

50

100

150

200

250

kW

Shoulder – Weekday

Summer – Weekday

Winter – Weekday

Shoulder – Weekend

Summer – Weekend

Winter – Weekend

Figure 3: Average daily (above) and seasonal (below) electrical load profiles, highlighting daily and seasonal variation in the base load.

47MARCH 2014 • ECOLI B R I U M

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Fans13%

Pumps15%

Chillers16%

Cooling towers 4%

PAC units8%

Car park lighting

1%

Base building lighting 3%

Miscellaneous 0%

Office equipment25%

Office lighting12%

Lifts3% 0

50

100

150

200

250

300

350

kW

0:003:00

6:009:00

12:0015:00

18:0021:00

Base building lighting

Office lighting

Office equipment

Car park lighting

Lifts

PAC units

Miscellaneous

Cooling towers

Chillers

Pumps

Fans

Average summer profileFigure 4: Electricity end-use breakdown for a 12-month period

(above) and an average business day in summer (right).

3513700 MJ

3500 MJ

648000 MJ

2607000 MJ 2525000 MJ

1004400 MJ

154800 MJ

658800 MJ 2322000 MJ 1098000 MJ861000 MJ

1500500 MJ

831000 MJ

505000 MJ

288000 MJ

173000 MJ115000 MJ

478800 MJ

122400 MJ

57600 MJ

327600 MJ

637200 MJ

547200 MJ

152000 MJ

162000 MJ

25200 MJ

58500 MJ

33300 MJ

PCM/reticulationlosses

Solar PV

Utility electricity

supply

Officeequipment

MiscellaneousTotal electricity supply

4,165,200 MJ

Utility gas supply5,133,000 MJ

Officelighting

Base buildinglighting

Car parklighting

Heatrejection

Fieldcooling

Fieldheating

Coolingtowers

Lighting

Fans

Pumps

Chillers

Flue losses

Microturbine

Heat recoveryHVAC electrical

Showertowers

PACunits

327600MJ

Boilers

Standinglosses

Solarhot water

Domestichot water

Combustionlosses

Reticulationlosses

electricity [MJ]

gas [MJ]

hot water energy [MJ]

heat (losses) [MJ]

Condenser water [MJ]

Chilled water [MJ]

Rejected heat [MJ]

Figure 5: Sankey flow diagram. This diagram demonstrates the flow of energy into the building and throughout its sub-systems. The diversity of energy sources and uses within the building is evident, as well as the degree of energy transfer and heat

recovery between the range of sub-systems. Note that thermal energy flows in the CHW and CDW networks are not quantified.

ECOLI BR I U M • MARCH 201448

F O R U M

from the micro-turbine, the screw chillers, the cooling towers or the shower towers. Production of cooling can either be after-hours and stored within phase-change material (PCM) tanks or delivered directly during occupied hours. Observations of the building through a range of conditions revealed that the system often failed to prioritise the most efficient cooling mode available. This regularly resulted in significant energy wastage overnight for charging of PCM tanks, which proved to be the issue responsible for the overnight operation (Figure 3). More importantly though, poor consideration of cooling modes meant the building was largely operating without an economy cycle, thus leading to excessive use of the electric chillers.

• Optimisation of HVAC parameters. A number of the temperature, flow and pressure set-points that the building’s air and water systems were operating to were fixed in spite of variable demand conditions. Examples included constant-pressure control for chilled water and heating hot water pumps, constant-flow control for air-handler fans, and constant water temperature control for chiller plant condenser water.

• Tuning of HVAC operation. A range of smaller operational issues were identified that summed up to a reasonable quantity of lost energy for the site. Such issues included general exhaust fans running when not required, car park ventilation fans running irrespective of CO set points, pumps running when there was no heating/cooling within the fluid they were circulating, heat exchangers (HEX) opening the primary valve without the secondary valve, and so on.

A comprehensive revision of the strategies and commissioning of the HVAC controls was recommended to address these issues, including improved economy cycle operation, vairable set-points for key water and air systems, and a general tightening up of HVAC control to avoid wasteful operation.

However, the physical components of a system must be operating reliably for controls measures to achieve their full potential. Observations of CH2’s plant suggested the system was generally in good working condition, but there was evidence of a modest range of less visible issues that may have been preventing optimum performance. The majority of these issues were consistent with the usual failure modes of commercial HVAC systems, including air within the water networks, instances of dubious sensor accuracy, valves failing to seal, compromised HEX efficiency and poor performance of PCM tanks. A tune-up process was recommended to help mitigate the risk they posed to the performance of the building.

EXAMPLES OF CONTROL OPPORTUNITIESA series of screenshots from the BMS are presented below with notes against the opportunities they highlight.

Erroneous cooling system operation during business hours

Figure 6 demonstrates the building’s cooling system operating on July 27, 2012. The following opportunities for improvement were observed:

• As noted in the yellow circle labelled “A”, the outside air conditions at this time were 12.5°C and 72%RH,

corresponding to a wet bulb temperature of approximately 10°C. In these cool conditions, the cooling towers are capable of providing sufficient cooling to the building, with no need for the chilled water plant. This opportunity exists for most of winter but was overlooked by the system’s control strategy.

• As noted in the green circles labelled “B”, there were a number of pumps operating at this time apparently for no purpose. The absorption chiller had faulted out of operation, preventing the cooling system from providing any cooling. However, the failure was not communicated to the pumps, and thus they were each running to circulate room-temperature water throughout the building.

PCM charging with chilled water

Figure 7 demonstrates the chilled water system operating at 04.00 on November 21, 2012. The chillers were found to be operating overnight to charge the PCM tanks. This operation appeared to occur regularly throughout the shoulder and summer months between the hours of 00.00 and 06.00 on business days. The design intent of the PCM charging process is to take advantage of cool overnight conditions and charge the tanks with the cooling towers to avoid having to use the electric chillers during the day. If the PCM tanks are performing ideally, charging them via the electric chillers overnight should not result in a significant loss of energy. However, there did appear to be a high level of energy loss associated with this operation.

Figure 6: Cooling system operating when “free cooling” is available from ambient conditions.

Figure 7: Chilled water system operating at 04.00 to charge the PCM tanks.

49MARCH 2014 • ECOLI B R I U M

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Logs of the charging and discharging process were plotted against the average tank internal temperature in Figure 8.

The following observations were made:

• While the charging process (signified by the decreasing tank temperature) lasted for approximately five hours from 00.00 to 05.00, the tanks were fully discharged (signified by increasing tank temperature) after one hour upon start-up.

• The temperature is continuously decreasing during the charging process. The temperature of a PCM remains constant while the material is undergoing a phase change (changing from liquid to solid). That the tank temperature was continuously decreasing during the charging process implied that there was no phase change within the tank; i.e., the chilled water was merely cooling the material down in its existing phase (most likely liquid). The thermal storage capacity of the tank relies on the material’s nature to absorb coolth as it changes from liquid to solid phase; thus the tanks provide minimal storage without the phase-change process.

Erroneous operation of heating plant and air-handling plant

Figure 9 demonstrates the outside air-handling plant operating on October 18, 2012. Several issues were observed with its operation:

• As circled in red and labelled “A”, the heating pump had been engaged for the air-handling plant despite the mild ambient

conditions (18.4°C). Heating should not be required in an office building with ambient conditions above 18.0°C.

• As circled in yellow and labelled “B”, the system elected to operate the heat reclaim pump from the condenser water loop to serve the heating needs of the air handlers at this time. However, the temperature of the flow into the HEX, out of the HEX, into the AHUs and out of AHUs was each measured at 19.5°C, indicating there was no transfer of heat occurring in the system and thus the pumps were not achieving anything.

• As circled in green and labelled “C”, the heating hot water network was engaged at this time. Inspection of the BMS heating demand indicated that the AHU system was registering a demand on the heating hot water plant despite not using the heating hot water.

Constant speed pumping

Figure 10 presents the operation of heating (in red) and cooling (in blue) reticulation in the building on October 18, 2012. We noted these pumps operating at the same speed across a range of different internal and ambient conditions. Introducing dynamic resets to the pressure set-points was recommended to help them turn down to meet demand, which would also apply more broadly to other air and water systems as well.

MEASURES FOR IMPLEMENTATIONThe report was delivered in December 2012, with recommendations made for wholesale revision to the HVAC controls in addition to a suite of hardware tuning items and minor retrofits. With budget awarded for FY13/14, at the time of writing the City of Melbourne and Exergy are in the planning phase for implementation of the first stage of measures. They are presented in Table 3.

Figure 11 demonstrates the measures improving the base building’s rating to 4.5 stars. However, it is important to note that the savings were conservatively calculated as what we expected to be available from an “install and leave it” type approach. We anticipate that an intensive process of monitoring and tuning will reveal greater potential from the building’s existing systems.

Crucial to the success of this project will be a functioning sub-metering system to inform a critique of each of the building’s

0

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12:0

0 A

M

1:00

AM

2:00

AM

3:00

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4:00

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6:00

AM

7:00

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8:00

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9:00

AM

10:0

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M

11:0

0 A

M

12:0

0 PM

1:00

PM

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3:00

PM

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6:00

PM

7:00

PM

8:00

PM

9:00

PM

10:0

0 PM

11:0

0 PM

Tem

per

atur

e (D

eg°C

)

PCM discharging process

Average internal tank tempPCM charging process

Figure 9: Air-handling plant engaging the heating system in mild conditions.

Figure 8: PCM charging and discharging process on the 14/11/12 demonstrating the disparity between charging

and discharging times.

Figure 10: Constant speed pumping control for heating and cooling systems.

F O R U M

features as they are plugged in and out of the control strategy. This process will serve to provide a blueprint for how the building’s complex array of sub-systems can best collaborate with each other. Furthermore, with this information the building will finally be in a position to provide feedback to the industry on the performance of the experimental technologies it features.

CONCLUSIONS1. CH2 is currently performing well below its potential due to

the state of the HVAC controls. It appears that the complexity associated with the building’s web of relatively unfamiliar sub-systems has led to a range of flawed strategies and operational issues.

2. The building is an excellent illustation of the importance of optimising control strategies and commissioning control behaviour for sub-systems, not only individually but also in their operation as a whole system and under numerous scenarios.

3. The building is expected to achieve 4.5 stars NABERS base building performance with the measures currently intended for implementation. Further improvement is expected to be realised with intensive monitoring and tuning.

4. Upgrade of the building’s sub-metering system, combined with a staged process of implementation and measurement is necessary not only to optimise the building’s operation but also to inform the industry on the performance of its more experimental technologies. This review marks the beginning of a project from which much more will hopefully be learnt regarding the performance of its many features. ❚

FOOTNOTES1. National Australian Built Environment Building Rating

System, www.nabers.gov.au2. See annual reports available online for CPA,

GPT Group and DEXUS. Each accessed 21/01/2014: http://www.cfsgam.com.au/au/property/cpa/Investor_

Centre/Reports_and_presentations/ http://www.gpt.com.au/Sustainability/Our-Environment/

NABERS-Ratings

http://dexus.com/investor/home.aspx

ACKNOWLEDGMENTSWe would like to acknowledge the keen assistance of Michele Leembruggen (Sustainability Branch), Allen McCowan (Property Services) and their colleauges within the City of Melbourne, as well as Matt Waller of Transfield Services and Peter Collins of Schneider Electric.

2.5 3 3.5 4 4.5 5 5.5 6Base Building NABERS Energy Rating

Monitoring and tuning

Existing rating

HVAC re-commissioning

Optimise after hours DHW servicing

Sub-metering and monitoring

HVAC controls revision

Upgrade CDW system to variable flow

BOH lighting controls

Figure 11: Base building NABERS improvement path.

Measure% 

Energy saving

Payback (yrs)

Base building NABERS 

star impact

HVAC controls revision of

re-commissioning19.7% 5.2 1.14

Upgrade supplementary CDW system to variable flow

1.4% 9.3 0.13

Optimise after-hours DHW

servicing3.9% 8.1 0.06

Back-of-house lighting controls 0.3% 22 0.02

Sub-metering verification and

monitoringn/a n/a n/a

Total 25.2% 7.2 1.36

About the authors

MatthewHoogland,M.AIRAH,isaseniorconsultantwithExergyAustraliabasedinMelbourne.Emailhimviamatt@xgl.com.au

DrPaulBannister,M.AIRAH,isthemangingdirectorofExergyAustralia,basedinCanberra.Emailhimviapaul@xgl.com.au

Table 3: Short-to-medium term measures for implementation.

DA27 + DA28Green Star recoGnition

Purchase online at www.airah.org.au

DA27 BUILDING COMMISSIONING

BUILDING COMMISSIONING DA27

••• 24

••• 25

The commissioning manager can assist the owner and

building designers define the POR, the content of which is

discussed in Section 5.

3.4.3. Assemble commissioning teamThe next step is to put together the commissioning team.

The role of the commissioning team is to oversee the entire

commissioning process.

The commissioning team will:• Provideaforumforintertradecommunication.• Provideamechanismfortheclearallocationofproject

responsibilities.• Participateincommissioningreviews.• Assistwithnon-conformanceresolution.• Approvethecommissioningandtuningplans.

• Approvethecommissioningreport.

The commissioning manager chairs the commissioning

team meetings and is ultimately responsible for assigning

commissioning task responsibilities and signing off on

required verification steps.Stakeholders that should be represented on the commissioning team include:• Owner’srepresentative.• Facilitymanagementstaff.• Maintenancemanager.• Occupantortenantrepresentative.• Maincontractor.

• Buildingservicessubcontractors.• Specificequipmentmanufacturers.• Buildingdesignersandarchitect.• Controlscontractororsupplier.• Buildingservicesdesigners.Not all of these stakeholders will be available at thebeginningoftheproject.Themake-upofthecommissioning team will evolve over the course of the

projectaskeystakeholdersbecomeinvolvedintheprocess,

anddependingonthecontractualstructureoftheproject.

Itisessentialhowever,thatallkeyprojectparticipantsare

included at the earliest possible stage to ensure that the

owner’sexpectationsandindividualprojectcommissioning

responsibilities are clearly allocated and understood. It is

also essential that once these stakeholders are engaged in

theproject,theactionsandresponsibilitiesthathavebeen

delegated to them and the commissioning expectations of

them are clearly communicated to them and understood

and accepted by them.Periodic meetings of the commissioning team are essential

toasuccessfulbuildingcommissioningprocess.Morefrequent team meetings are generally required during the

later stages of construction, testing and handover as this

isthephaseoftheprojectwhenmosterrorsorconflicts

can arise and when there is the least amount of time and

resources available to resolve them.3.4.4. Pre-design meetingAnimportantstepintheprocessistoholdapre-design

meeting of the commissioning team. This is an opportunity

for the commissioning manager and owner to introduce all

stakeholders, explain the commissioning process, allocate

all responsibilities (clarifying any overlaps), coordinate the commissioning activities, and clearly outline the expectations for all parties.

The owner should fully empower the commissioning manager at this time to ensure that all stakeholders in the

projectarefullyawareoftheowner’sexpectationswithregardtobuildingcommissioning.Thepre-designmeeting

is also an opportunity for commissioning team members to

sharelessonslearnedfrompreviouscommissioningprojects.

3.4.5. Roles and responsibilitiesNotallprojectstakeholders(e.g.specialistcontractors

andsubcontractors)willbeengagedintheprojectat

this early stage however, their roles and responsibilities

still need to be allocated and defined at this point. Once

thesestakeholdersareengagedintheprojectandjoin

the commissioning team they should be asked to sign off

or confirm the roles and responsibilities that have been

allocated to them. These roles and responsibilities should

be detailed as part of the conditions of contract, not after

the awarding of the contract or subcontract works.3.4.6. Define scope of workOneofthepre-designdeliverablesofthecommissioning

teamisawell-definedandagreedscopeofworkforthe

projectsothatthedesignphasecanbecarriedout.The

scope of work will form part of the commissioning plan.3.4.7. Draft commissioning plan (outline)Once the scope of work has been defined, an outline of the

commissioning plan will be developed by the commissioning

manager. The commissioning plan is a document that evolves

withtheprojectandisreviewedandupdatedatseveralstages

duringtheproject.Seefigure3.2.Developinganoutlineofthecommissioningplanatthepre-designstagehelps

the commissioning team to focus on the commissioning

requirementsofthedesignstageoftheproject.The commissioning plan serves as a focus point for the commissioningteamthroughouttheproject.Atpre-design

stage it will specify the design related commissioning tasks

andschedules.Atdesignstageitwillspecifytheconstruction

relatedcommissioningtasksandschedules.Atconstruction

stage it will specify the handover related commissioning

tasksandschedules.Athandoverstageitwillspecifythe

building tuning related commissioning tasks.

Figure 3.2: Commissioning Plan updated after each phase

Finalcommissioningplan

Install

Test

Design

Outline

The commissioning process

Figure 3.1: The Commissioning Process

•  Assign a commissioning manager•   Document owner’s requirements•  Assemble commissioning team

•   Pre-design commissioning meeting•  Draft scope of work•  Outline commissioning plan

Pre design

•  System design reviews•   Design review reports•  Commissioning ream review

•   Design issues and changes•  Commissioning specification•  Updated commissioining plan (Design)

Design

•  Construction documentation review•   Systems installation / site review•  Building documentation review

•   Documenting issues and changes•  Finalise test procedures•  Updated commissioning plan (Install) 

Install

•  Test reports•   Diagnostic monitoring•  Functional tests and TAB

•   Integrated tests•  Building preformance tests and seasonal tests•  Updated commissioning plan (Test)

Test

•  Final building documentation•  Training•  Operations review and building tuning

•   Final commissioning report•  Lessons learned at meeting

Handover

•  Tuning and maintenance•   Persistance strategies•  Continuous commissioning

•   Recommissioning•  Retrocommissioning•  Replacement

Owning

DA27 BUILDING COMMISSIONING

BUILDING COMMISSIONING DA27

••• 24

••• 25

The commissioning manager can assist the owner and

building designers define the POR, the content of which is

discussed in Section 5.

3.4.3. Assemble

commissioning team

The next step is to put together the commissioning team.

The role of the commissioning team is to oversee the entire

commissioning process.

The commissioning team will:

• Provideaforumforintertra

decommunication.

• Provideamechanismfortheclea

rallocationofproject

responsibilities.

• Participateincommissioningrev

iews.

• Assistwithnon-conform

anceresolution.

• Approvethecommissioningan

dtuningplans.

• Approvethecommissioningrep

ort.

The commissioning manager chairs the commissioning

team meetings and is ultimately responsible for assigning

commissioning task responsibilities and signing off on

required verification steps.

Stakeholders that should be represented

on the commissioning team include:

• Owner’srepresentative.

• Facilitymanagementstaff.

• Maintenancemanager.

• Occupantortenantrep

resentative.

• Maincontractor.

• Buildingservicessubcon

tractors.

• Specificequipmentmanufacturer

s.

• Buildingdesignersanda

rchitect.

• Controlscontractororsu

pplier.

• Buildingservicesdesign

ers.

Not all of these stakeholders will be available at

thebeginningofthepro

ject.Themake-upofthe

commissioning team will evolve over the course of the

projectaskeystakeholde

rsbecomeinvolvedintheprocess

,

anddependingonthec

ontractualstructureoft

heproject.

Itisessentialhowever,th

atallkeyprojectparticip

antsare

included at the earliest possible stage to ensure that the

owner’sexpectationsan

dindividualprojectcom

missioning

responsibilities are clearly allocated and understood. It is

also essential that once these stakeholders are engaged in

theproject,theactionsa

ndresponsibilitiesthatha

vebeen

delegated to them and the commissioning expectations of

them are clearly communicated to them and understood

and accepted by them.

Periodic meetings of the commissioning team are essential

toasuccessfulbuilding

commissioningprocess.More

frequent team meetings are generally required during the

later stages of construction, testing and handover as this

isthephaseoftheproje

ctwhenmosterrorsorconflicts

can arise and when there is the least amount of time and

resources available to resolve them.

3.4.4. Pre-design meeting

Animportantstepintheproce

ssistoholdapre-desig

n

meeting of the commissioning team. This is an opportunity

for the commissioning manager and owner to introduce all

stakeholders, explain the commissioning process, allocate

all responsibilities (clarifying any overlaps), coordinate

the commissioning activities, and clearly outline the

expectations for all parties.

The owner should fully empower the commissioning

manager at this time to ensure that all stakeholders in the

projectarefullyawareof

theowner’sexpectation

swith

regardtobuildingcommissioning.Th

epre-designmeeting

is also an opportunity for commissioning team members to

sharelessonslearnedfro

mpreviouscommissioningpro

jects.

3.4.5. Roles and responsibilities

Notallprojectstakehold

ers(e.g.specialistcontra

ctors

andsubcontractors)wil

lbeengagedinthepro

jectat

this early stage however, their roles and responsibilities

still need to be allocated and defined at this point. Once

thesestakeholdersaree

ngagedintheprojecta

ndjoin

the commissioning team they should be asked to sign off

or confirm the roles and responsibilities that have been

allocated to them. These roles and responsibilities should

be detailed as part of the conditions of contract, not after

the awarding of the contract or subcontract works.

3.4.6. Define scope of work

Oneofthepre-designde

liverablesofthecommissioning

teamisawell-definedandag

reedscopeofworkfort

he

projectsothatthedesig

nphasecanbecarriedo

ut.The

scope of work will form part of the commissioning plan.

3.4.7. Draft commissioning

plan (outline)

Once the scope of work has been defined, an outline of the

commissioning plan will be developed by the commissioning

manager. The commissioning plan is a document that evolves

withtheprojectandisre

viewedandupdatedats

everalstages

duringtheproject.Seefig

ure3.2.Developinganou

tline

ofthecommissioningplanatthepre-

designstagehelps

the commissioning team to focus on the commissioning

requirementsofthedesignstageo

ftheproject.

The commissioning plan serves as a focus point for the

commissioningteamthroughout

theproject.Atpre-desig

n

stage it will specify the design related commissioning tasks

andschedules.Atdesign

stageitwillspecifythec

onstruction

relatedcommissioningtasksandsched

ules.Atconstruction

stage it will specify the handover related commissioning

tasksandschedules.Atha

ndoverstageitwillspecif

ythe

building tuning related commissioning tasks.

Figure 3.2: Commissioning Plan updated after each phase

Final

commissioning

plan

Install

Test

Design

Outline

The commissioning process

Figure 3.1: The Commissioning Process

•  Assign a commissioning man

ager

•   Document owner’s requireme

nts

•  Assemble commissioning te

am

•   Pre-design commissioning 

meeting

•  Draft scope of work

•  Outline commissioning plan

Pre design

•  System design reviews

•   Design review reports

•  Commissioning ream review

•   Design issues and changes

•  Commissioning specification

•  Updated commissioining pla

n (Design)

Design

•  Construction documentatio

n review

•   Systems installation / site re

view

•  Building documentation rev

iew

•   Documenting issues and ch

anges

•  Finalise test procedures

•  Updated commissioning plan

 (Install) 

Install

•  Test reports

•   Diagnostic monitoring

•  Functional tests and TAB

•   Integrated tests

•  Building preformance tests

 and seasonal tests

•  Updated commissioning plan

 (Test)

Test

•  Final building documentati

on

•  Training

•  Operations review and build

ing tuning

•   Final commissioning report

•  Lessons learned at meeting

Handover

•  Tuning and maintenance

•   Persistance strategies

•  Continuous commissioning

•   Recommissioning

•  Retrocommissioning

•  Replacement

Owning

APPLICATION MANUAL

THE AUSTRALIAN INSTITUTE OF REFRIGERATION, AIR CONDITIONING AND HEATING

BUILDING COMMISSIONING

DA27

DA27 Building Commissioning and DA28 Building Management and Control Systems have been recognised in a recent GBCA technical clarification. This means that Australian industry can work with processes and documents that they understand. References are to Australian law, Australian regulations, Australian Standards and Australian practices – and all in a language and vernacular that Australian industry can understand.

DA28 BUILDING MANAGEMENT & CONTROL SYSTEMS BUILDING MANAGEMENT & CONTROL SYSTEMS DA28

••• 62

••• 63

as-installed drawings reflect what has been corrected

to gain a more efficient and manageable building system.

10.9. System management

10.9.1. System access

It is important to decide who has access to the BMCS

controls. The following stakeholders generally need some

form of access to system settings:

• System operators – Day to day operational tasks.

• Maintenance providers

– System interrogation, monitoring.

• Building tuning team – Fine tuning control loops

• Specialist or vendor representatives

– Updates and fixes.

The level of access and authority to make changes

must be clearly identified and defined for each individual.

10.9.2. Change management

It is important for BMCS, or any DDC control system, that

a formal change management system is put in place.

Unauthorised changes and quick fixes are common

reasons why system controls operate inefficiently. Only

specified people should be given access to the BMCS

and the responsibility or authority for changing controls

settings, control routines, and controls logic should be

nominated.

• Control settings – Changing set points and targets,

room temperature settings, set back temperatures.

• Control routines – Changing parameters

associated with systems control philosophy.

• Control logic – Changing code

in the controller programming.

When making changes to system operating

controls or settings, it is important to consider all

of the consequences of the change made. The system

should be set up to record and show who was logged

onto the system, what changes if any were made, and

the underlying reasons why the changes were made.

10.9.3. Documenting changes

Ideally a building tuning plan should be in place to

introduce a standardised process for managing changes

to the control system. All changes that are authorised

should be fully documented and the building

documentation and BMCS information updated as

appropriate.

10.9.4. Verifying systems

Even with strong policies in place, it may be difficult

to guarantee that unauthorised changes have not been

made and it is worthwhile to periodically verify and sign

off that rogue control strategies or changes have not been

implemented.

10.10. Post occupancy

evaluation

Also termed building performance evaluation, this

activity focuses on determining how well the building

is meeting its defined operating requirements and assesses

the level of satisfaction or dissatisfaction of building

occupants and users.

Post occupancy evaluation usually focuses on energy

usage figures and occupant evaluation surveys, although

criteria will vary from facility to facility.

Any evaluation process needs to include a formal

evaluation of the building performance information

and survey results, generally by a tuning or building

performance team.

10.11. Performance review

The specific requirements of the building or individual

spaces may change over time and there should be

some form of review to adjust systems to the specific

requirements. Where no particular changes have occurred,

systems will still need to be finetuned. Minor changes

may lead to a recommissioning program whereas major

changes in the operating requirements may lead to system

or building retrocommissioning.

• Fine tuning – Uses tests and procedures

as detailed in the building tuning manual.

• Recommissioning – Uses the same tests and

procedures as utilised for the original commissioning

program.

• Retrocommissioning – Uses new tests and

procedures developed specifically for the new

or modified system.

10.12. Recommissioning

Recommissioning begins with a review of the project

operating requirements (POR) to determine what, if any,

changes have occurred. The POR needs to be updated

or confirmed prior to any recommissioning activities

commencing.

If changes have occurred, systems are reviewed to

establish if corresponding changes to equipment,

controls or operation procedures are required.

Systems are then fully surveyed and a list of findings

or issues compiled.

System trend logs or functional performance tests may

be used to determine if the systems meet the performance

defined in the reviewed and updated project operating

requirements (POR).

10.13. Upgrades

Replacement strategy – scheduling the replacement

of inefficient equipment with modern high efficiency

alternatives (always review the load requirements for changes).

This Appendix provides a broad overview of control system

fundamentals and explains some of the common terms

used when discussing control systems. For more detailed

technical information on any of this material refer to CIBSE

Guide H Building Control Systems or similar publications.

Manual control requires direct control of a system by

human intervention. Automatic controls function without

direct human intervention once set in motion. Automatic

controls act to maintain a predetermined set point in

response to changing conditions.

At its most fundamental, a control system comprises

a sensor, a controller, a controlled device, a process,

and a feedback to the system. Closed loop systems

have a direct feedback via the sensor; open loop systems

have no direct feedback. The set point is the desired

or pre-set value of the variable for the feedback loop

to compare against, e.g. the temperature of a space

or the pressure of a fluid.

Figure A1: Basic control loop

A sensor detects and measures a variable and sends this

information to the controller. Sensors typically measure

temperature, pressure, humidity, velocity, flow, illuminance,

movement, substance concentration, electrical resistance, or

electronic voltage. Sensor output becomes controller input.

The controller receives the information from the sensor

and uses a pre set logic or control algorithm to compute

an output signal which it sends to the controlled device.

Controller output becomes controlled device input.

The controlled device receives the information from the

controller and acts on it to make the required change to

the system. Examples of controlled devices are modulating

valves and dampers, lighting dimmers, variable speed

motors (that drive fans, pumps and compressors), electrical

or electronic switches and capacitors.

A sensor, controller and controlled device can all live

in the same box or they can be in three separate places.

They need to be connected to communicate, connections

can be wired or wireless. Sensor output becomes

controller input and controller output becomes device

input. A thermostat is both a sensor and a controller; a

thermostatic valve is a sensor, a controller and a controlled

device. The load or process typically includes building

ventilation, cooling, heating, lighting, transport, and

security access.

Figure A2: DDC inputs and outputs

A direct acting control action means the output increases

with increases in the measured variable.

A reverse acting control action means the output

decreases as the measured variable increases.

Examples of controllers are thermostats, programmable

timers, microprocessor controls, direct digital control

systems (DDC), and building management and control

systems (BMCS). How the controller functions, its internal

logic, determines the relationship between the controllers

input and output. This is called the control response.

Typical control responses employed in building HVAC are:

• Two position – This is essentially an on/off control

based on the specified set point and differential.

The output is off when the set point is reached,

and on when the difference between the set point

and the measured variable (the differential) reaches

the specified value.

Controls fundamentalsAppendix A

CCD

CoolingCoil

S

Controller

ControlledDevice

ChilledWaterSupply

ChilledWater Return

Controlled Medium

(Air temperature)

NormallyOpen

Sensor

CSController

Into DDCOut of DDC

OUTPUTLOGIC

INPUT

CDControlledDevice

Sensor

DA28 BUILDING MANAGEMENT & CONTROL SYSTEMSBUILDING MANAGEMENT & CONTROL SYSTEMS DA28

••• 62

••• 63

as-installed drawings reflect what has been corrected

to gain a more efficient and manageable building system.10.9. System management10.9.1. System accessIt is important to decide who has access to the BMCS

controls. The following stakeholders generally need some

form of access to system settings:• System operators – Day to day operational tasks.• Maintenance providers – System interrogation, monitoring.• Building tuning team – Fine tuning control loops

• Specialist or vendor representatives – Updates and fixes.

The level of access and authority to make changes must be clearly identified and defined for each individual.10.9.2. Change managementIt is important for BMCS, or any DDC control system, that

a formal change management system is put in place.

Unauthorised changes and quick fixes are common reasons why system controls operate inefficiently. Only

specified people should be given access to the BMCS

and the responsibility or authority for changing controls

settings, control routines, and controls logic should be

nominated.• Control settings – Changing set points and targets,

room temperature settings, set back temperatures.• Control routines – Changing parameters

associated with systems control philosophy.• Control logic – Changing code in the controller programming.When making changes to system operating

controls or settings, it is important to consider all of the consequences of the change made. The system

should be set up to record and show who was logged

onto the system, what changes if any were made, and

the underlying reasons why the changes were made.10.9.3. Documenting changesIdeally a building tuning plan should be in place to introduce a standardised process for managing changes

to the control system. All changes that are authorised

should be fully documented and the building documentation and BMCS information updated as appropriate.

10.9.4. Verifying systemsEven with strong policies in place, it may be difficult to guarantee that unauthorised changes have not been

made and it is worthwhile to periodically verify and sign

off that rogue control strategies or changes have not been

implemented.

10.10. Post occupancy evaluationAlso termed building performance evaluation, this activity focuses on determining how well the building

is meeting its defined operating requirements and assesses

the level of satisfaction or dissatisfaction of building occupants and users.

Post occupancy evaluation usually focuses on energy

usage figures and occupant evaluation surveys, although

criteria will vary from facility to facility.Any evaluation process needs to include a formal evaluation of the building performance information and survey results, generally by a tuning or building performance team.

10.11. Performance reviewThe specific requirements of the building or individual

spaces may change over time and there should be some form of review to adjust systems to the specific

requirements. Where no particular changes have occurred,

systems will still need to be finetuned. Minor changes

may lead to a recommissioning program whereas major

changes in the operating requirements may lead to system

or building retrocommissioning.• Fine tuning – Uses tests and procedures as detailed in the building tuning manual.

• Recommissioning – Uses the same tests and procedures as utilised for the original commissioning

program.• Retrocommissioning – Uses new tests and

procedures developed specifically for the new or modified system.

10.12. RecommissioningRecommissioning begins with a review of the project

operating requirements (POR) to determine what, if any,

changes have occurred. The POR needs to be updated

or confirmed prior to any recommissioning activities commencing.

If changes have occurred, systems are reviewed to establish if corresponding changes to equipment, controls or operation procedures are required.Systems are then fully surveyed and a list of findings

or issues compiled.System trend logs or functional performance tests may

be used to determine if the systems meet the performance

defined in the reviewed and updated project operating

requirements (POR).

10.13. UpgradesReplacement strategy – scheduling the replacement of inefficient equipment with modern high efficiency alternatives (always review the load requirements for changes).

This Appendix provides a broad overview of control system

fundamentals and explains some of the common terms

used when discussing control systems. For more detailed

technical information on any of this material refer to CIBSE

Guide H Building Control Systems or similar publications.Manual control requires direct control of a system by

human intervention. Automatic controls function without

direct human intervention once set in motion. Automatic

controls act to maintain a predetermined set point in

response to changing conditions.At its most fundamental, a control system comprises

a sensor, a controller, a controlled device, a process, and a feedback to the system. Closed loop systems have a direct feedback via the sensor; open loop systems

have no direct feedback. The set point is the desired

or pre-set value of the variable for the feedback loop

to compare against, e.g. the temperature of a space or the pressure of a fluid.

Figure A1: Basic control loopA sensor detects and measures a variable and sends this

information to the controller. Sensors typically measure

temperature, pressure, humidity, velocity, flow, illuminance,

movement, substance concentration, electrical resistance, or

electronic voltage. Sensor output becomes controller input.The controller receives the information from the sensor

and uses a pre set logic or control algorithm to compute

an output signal which it sends to the controlled device.

Controller output becomes controlled device input.The controlled device receives the information from the

controller and acts on it to make the required change to

the system. Examples of controlled devices are modulating

valves and dampers, lighting dimmers, variable speed

motors (that drive fans, pumps and compressors), electrical

or electronic switches and capacitors.A sensor, controller and controlled device can all live in the same box or they can be in three separate places.

They need to be connected to communicate, connections

can be wired or wireless. Sensor output becomes controller input and controller output becomes device

input. A thermostat is both a sensor and a controller; a

thermostatic valve is a sensor, a controller and a controlled

device. The load or process typically includes building

ventilation, cooling, heating, lighting, transport, and security access.

Figure A2: DDC inputs and outputsA direct acting control action means the output increases

with increases in the measured variable.A reverse acting control action means the output decreases as the measured variable increases.Examples of controllers are thermostats, programmable

timers, microprocessor controls, direct digital control systems (DDC), and building management and control

systems (BMCS). How the controller functions, its internal

logic, determines the relationship between the controllers

input and output. This is called the control response.Typical control responses employed in building HVAC are:• Two position – This is essentially an on/off control

based on the specified set point and differential. The output is off when the set point is reached, and on when the difference between the set point and the measured variable (the differential) reaches the specified value.

Controls fundamentals

Appendix A

C

CD

CoolingCoil

S

Controller

ControlledDeviceChilledWaterSupply

ChilledWater Return

Controlled Medium(Air temperature)

NormallyOpen

Sensor

CS

Controller

Into DDCOut of DDC

OUTPUTLOGIC

INPUT

CD ControlledDevice

Sensor

APPLICATION MANUAL

THE AUSTRALIAN INSTITUTE OF REFRIGERATION, AIR CONDITIONING AND HEATING

DA28BUILDING MANAGEMENT

AND CONTROL SYSTEMS

(BMCS)