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Lucid Consulting Australia for Brimbank City Council – Lessons Learnt Report #[3]
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Brimbank Aquatic and Wellness Centre – Lessons Learnt Report #3
1. PROJECT BACKGROUND
The Brimbank Aquatic and Wellness Centre Integrated Energy System project is a carbon-neutral,
renewable energy-powered aquatic centre in Keilor Downs, Melbourne.
To transition away from gas, Brimbank City Council pursued an ‘all-electric’ building services
approach through the application of heat-pump technology (4-pipe simultaneous and standard
reverse cycle technologies), thermal energy storage and significant extents of solar PV renewable
energy. Supplied with grid electricity from 100% renewable sources (through the Victorian Energy
Collaboration - VECO), the facility is operationally carbon neutral.
Based on interviews with members of the Architect, Contractor and ESD Consultant, this ‘Lessons Learnt’
report provides a summary of key issues pertaining to the ‘all-electric’ building services approach that
arose during the early stages of operation of the facility.
2. EXECUTIVE SUMMARY
After one year of operation, it can be concluded that the facility operates while meeting
excellent levels of energy efficiency, however, there are still a number of teething issues to
be resolved.
The current sub-metering system does not provide sufficient information for a
comprehensive performance assessment of the key equipment of the thermal plant.
Calibration issues within the EMS further aggravate the assessment.
Only minor amounts of thermal energy were provided by the backup gas boiler. Whether the
gas boiler was activated as a result of control issues of the boiler itself or of a capacity
shortage of the heat pumps can currently not be answered due to these sub-metering and
calibration limitations.
3. KEY LEARNINGS
Category:
Technical
3.1----------------------------------------------------------------------------------------------------------------------
Lesson learnt title:
The current sub-metering system does not provide sufficient information
for a comprehensive performance assessment of the key equipment of the thermal plant.
Detail:
The quarterly performance assessment has shown that the resolution of the sub-metering
system is too low to allow for a comprehensive analysis of the key components of the
thermal plant which is the heart of the building services of an all-electric aquatic centre. More

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Lucid Consulting Australia for Brimbank City Council – Lessons Learnt Report #[3]
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detail is required for each of the individual heat pumps, the large-scale solar PV system and
the thermal energy storage.
Implications for future projects:
Extra care should be taken when designing and specifying the sub-metering system on all
electric aquatic centres. The sub-metering strategy should not only be informed by
overarching sustainability frameworks like Green Star or NABERS, but rather be tailored to
the building services design such that crucial equipment with higher complexity (e.g. heat
pumps or thermal energy storage) can be monitored in greater/sufficient detail.
3.2----------------------------------------------------------------------------------------------------------------------
Lesson learnt title:
The data records within the EMS indicate calibration issues of the sub
metering systems in some areas.
Detail:
There are several sub-meters that provide implausible data, which compromises the
performance analysis of the facility. This analysis is crucial to rectify the teething issues of
the facility in the first year of operation.
For example, the EMS energy sub-meter for the solar PV system has shown substantially
less PV energy production than what was recorded within the proprietary monitoring platform
of the inverters. Implausible data provided by the thermal energy meter of the gas boiler is
another example of occurring calibration issues within the sub-meter system. While there is
a logical upward trend in the monthly gas consumption of the boiler when moving from
autumn to winter, the energy output of the gas boiler in the same period is trending
downwards. There were also unrealistically high thermal energy outputs recorded for all heat
pumps on several days in September which also points to calibration or data conversion
issues within the sub-metering system.
Implications for future projects:
In the first year of operation, the mechanical contractor should carry out monthly checks of
the EMS and BMS data to timely identify and rectify any calibration or conversion issues
within the sub-metering system.
3.3----------------------------------------------------------------------------------------------------------------------
Lesson learnt title:
The backup gas boiler operated throughout the year, however, with little
contribution to the overall thermal energy generated by the thermal plant.
Detail:
BAWC is intended to be run as an all-electric facility, with a conventional gas boiler system
as a backup heating source. In the first year of operation, the gas boiler was utilised nearly

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Lucid Consulting Australia for Brimbank City Council – Lessons Learnt Report #[3]
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every month. However, the overall contribution of the gas boiler to the total thermal energy
generation of this facility was minor (<4% per month).
A correlation between low ambient air temperatures (and therefore increased heating
Loads) and the use of the gas boiler could be identified. The gas boiler seems to be
activated at times when the daily minimum ambient temperature falls below ~5°C.
At this stage, due to insufficient metering, it is not possible to carry out a detailed analysis of
the heat pumps to determine whether the operation of the gas boilers is initiated by a
capacity shortage of the heat pumps at low ambient air temperature conditions or by
inadequate control parameters of the gas boilers.
Implications for future projects:
As per the comments in section 3.2, a sub-metering system that provides a comprehensive
picture of the heat pumps is required. The sub-metering system should have the ability to
provide data from which the unitary Coefficient of Performance (COP) of each heat pump
can be derived. This is crucial to assess the capacity of the heat pumps available to the
thermal plant at times of high thermal loads and low ambient air temperatures. A capacity
shortage of the heat pump might have initiated the operation of the boilers. Understanding
the thermal capacity fluctuation of heat pumps in aquatic centres for this climate is important
when designing future all-electric aquatic centres, especially when those are not equipped
with backup gas boilers.
3.4----------------------------------------------------------------------------------------------------------------------
Lesson learnt title:
A static and simplified control strategy might lead to an inadequately
utilised thermal energy storage (TES).
Detail:
The sub-metering of the thermal energy storage is insufficient to complete a detailed
assessment of its performance. At this stage, the TES is only equipped with a few
temperature sensors. The quantities of energy stored in and discharged from the TES
cannot be determined due to missing thermal energy meters.
The TES has mainly been operated on a static time clock to charge the storage during the
day and discharge it in the early morning. The period between the end of the charging
process and the beginning of the discharging process is in the order of 8 hours at which
standing losses occur. The thermal demand of the facility would most likely allow for an
earlier discharge of the TES.
More investigation on optimising the control strategy of the TES is needed.

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Lucid Consulting Australia for Brimbank City Council – Lessons Learnt Report #[3]
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Implications for future projects:
Extensive analysis of the TES control strategies should be carried out in the very early
stages of the design of future facilities of this type. The sub-metering and control system
shall be equipped with all data points needed to enable the identified control strategies.
3.5----------------------------------------------------------------------------------------------------------------------
Lesson learnt title:
An overall excellent energy efficiency has been determined for this
facility.
Detail:
The project team has determined and benchmarked the Energy Utilisation Intensity (EUI) of
BAWC. It was indicated that the BAWC’s EUI is 76% lower compared to conventional peer
facilities in Victoria, which underlines an overall excellent energy efficiency of the building.
Furthermore, the centre has achieved an estimated 52% reduction in total energy after the
assumed conversion of gas heating to electrical heating, proving the value of high quality
building envelope ESD treatments in building design.
The effects of this efficiency present in the centre’s energy bills, as our updated Energy
Financial Model shows a yearly saving of $267,734 per year in operation compared to a
reference equivalent gas boiler design, using the same consumption. The cost premium of
the BAWC heat pump and TES design was approximately $1.2m meaning that the cost of
the all-electric design has a payback period of 4.2 years.
Implications for future projects:
BAWC is an example of an aquatic centre with all-electric building services with excellent
energy efficiency outcomes. This is encouraging for future developments of this type to
pursue an all-electric building services design.
4. CONCLUSION:
We conclude that the facility demonstrated a high level of energy efficiency during its first
year of operation.
In the overall context, only minor amounts of thermal energy were provided by the gas boiler.
Whether the gas boiler was activated as a result of control issues of the boiler itself or of a
capacity shortage of the heat pumps can currently not be answered.
The sub-metering system needs to be further extended to provide an adequate visibility of
the performance of the key equipment of the facility.