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Case Study

Project Summary The Opportunity
Centro Hilton is a shopping center located in
Cowandilla, South Australia. The center operates
7 days a week and accommodates one major and
10 minor retailers and a café. 150 parking garages
are available and can be accessed via a ramp for
ground level.
Air conditioning in the mall area is via two roof
mounted ducted air conditioning units and natural
ventilation via automatic doors located at two
pedestrian entrances.
The enclosed parking garage is served by fluorescent
lighting together with three 4HP exhaust fans to
maintain ventilation and reduce CO levels. These
lights and fans were previously controlled by a time
clock situated in the main electrical switchboard
which activated these services daily between 7.30am
and 9.30pm each day.
There are a number of floodlights serving the
ground level open carpark and perimeter fluorescent
lighting to the building exterior for safe access and
after-hours security. These services were previously
controlled via a time switch set to pre-determined
operating hours. A manual override switch located
inside the main switchboard provides additional
external lighting control for cleaners and trades staff
when necessary.
During the detailed site audit, it was noted that
the operation of the parking garage exhaust
fans could be better managed through
implementing low cost energy conservation
measures (ECMs). The implementation of these
ECMs would not only control the speed of the
fans depending on the number of cars entering
and exiting the parking garage but also stop
when the parking garages were empty. The
ECMs would save Centro Hilton a tremendous
amount of energy as well as increase the life of
their existing equipment over the long term.
Another opportunity was identified as the
center has two rooftop mounted packaged
air conditioning units servicing the mall areas,
and these were also controlled via a time clock
mounted with in the air conditioning control
panel on the roof.
The Solution
The Results The parking garage fan operation and energy use were recorded over a period
of one month prior to commencing the upgrade. Following the operation of the
new Optergy BMS, energy use for the parking garage fans reduced by 90% in
one calendar month. The saving in energy equated to projected annual savings
of $10,000 based on current energy costs. The project had a simple payback of
less than one year.
Additional savings were achieved by exercizing better control of external parking
and security lighting.
The push button linked to the BMS for control of external lighting systems negates
any unnecessary energy use whenever lights are accidentally left on.
Lux control for the open car park lighting is also managed through the Alerton
BMS. This provides added levels of safety where, in time of inclement weather,
parking garage lights automatically get activated during day time.
Remote access to the Optergy BMS allows site maintenance staff to remotely
connect from other locations to make simple changes and adjustments which
save time and money.
• $10,000 Savings per year
• Payback less than one year
• 90% Energy Savings in
one month
A simplified Optergy Building Management System (BMS) to provide user friendly
time schedule control for mall air conditioning and lighting, and parking garage
fans operation.
Light level (Lux) monitoring and control for external parking and security lighting.
A push button switch installed in the cleaner’s room which would provide
adjustable time period control for after-hours mall and parking area lighting
and would switch off automatically after a pre-determined period.
Supply, installation and programming of variable speed drives (VSDs) for the
enclosed parking garage exhaust fans coupled with Carbon Monoxide (CO)
monitoring and fan operational control.
Remote access to the new Optergy BMS was provided by using the existing
CCTV data link between the shopping center and the State Administration office.
A “stand alone” electrical meter that records total energy use, power quality
characteristics for the incoming power supply, and “time of use” details of power
consumption. This data could be readily accessed via the local control panel with
all database information held securely on site, and periodically backed up.

Completion of Installation
Site work was coordinated with Centro Hilton’s maintenance electrician to ensure no inconvenience was caused to shoppers and tenants.
Work in the parking garages and other miscellaneous work was completed outside of normal business hours to ensure the mall and
parking garages remained completely accessible during operating hours. The project was delivered on-time and under budget.
About Optergy
Australia, UK, Malaysia, Singapore & USA
Optergy is a technology company dedicated to improving the business
of managing facilities with tools to improve efficiency, performance and
processes, whilst providing key stakeholders with data and reporting to
make informed strategic decisions. From the simplest building to the largest
complex enterprise, our client base is extensive and includes professionals
in the education, healthcare, commercial, retail and government sectors.

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