Possibly the world’s first variable volume chilled beam solution and biggest LED installation in the southern hemisphere are just two examples of innovations Norman Disney & Young (NDY) delivered at Barangaroo.
Designing the mechanical services solution from the ground floor up, NDY director Tim Spies has managed eight tenant fitouts to date including Westpac. NDY worked in collaboration with Lendlease Design (LLD) who undertook design of the basement and infrastructure including the district cooling plant and the initial concept design for the towers. It was the close working relationship with Lend Lease that enabled the project to achieve such a high level of success to date.
He said Barangaroo’s highly sustainable achievements have really pushed the boundaries of what was achievable, but the team led by LLD Sustainability has secured a 5-star Nabers rating and a 6-star Green Star.
“It really did test the mettle of the team to achieve these lofty goals,” Spies said.
“What’s unique to the building is the floor to ceiling height of 2,900mm which is a first for a new development.
“The raised floor put pressure on services in the ceiling.
“The floor to slab heights haven’t changed with 3,850mm slab to slab height plus the floor plates are large – 2,300 square metres. “Distributing services at such a large floor plate brought challenges. The cooling plant is five metres below sea level so that also brought challenges for the team to ensure it remained water tight.”
Spies said most traditional ceiling voids have dedicated zones for services such as ductwork, cable trays, pipework and sprinklers.
At Barangaroo, he said there are no specific zones for services, it's a shared services zone.
“Everyone is competing for the same amount of space which is limited,” he said.
One of the most innovative features of Barangaroo is the chilled beam solution.
Spies said there are two types of chilled beam solutions – passive and active.
“We have active chilled beams on the perimeter and passive chilled beams with 100 per cent dehumidified outside air in the central zone to provide occupant comfort,” he said.
“Chilled beams are much lower energy users than traditional VAV systems because pumping water around is less energy consuming than pumping air.
“One of the ways sustainability targets were met is through demand controlled outside air. The building looks at the CO2 levels in the space and ramps the fresh air up or down to set areas. We all know that most office buildings are never occupied at 100 per cent so why provide 100 per cent fresh air when it is not necessary?
“However, it does have to be tempered with the chilled water ensuring we don’t have any sweating of the chilled beams.”
Spies said it is the largest installation in Australia and chilled beams are not a new technology.
“These solutions have been used in Europe for a long time but are fairly new in the Australian market because of concern about the solution’s ability to provide the right cooling output.
“The other problem is controlling humidity in the space and preventing rain. That’s when condensate starts to drip.
“From an energy point of view, it’s fantastic technology but it must be installed, designed and managed correctly.”
One of the unique features of the chilled beam solution at Barangaroo is that it incorporates variable volume, which NDY believes is a world first. The norm is to utilise constant volume.
“To do this required a substantial amount of testing in the factory in Germany. Staff spent eight weeks over there testing heating and cooling,” Spies said. “Heating was our biggest concern.”
Spies said the electrical infrastructure is also unique at Barangaroo.
He said it is distributed at 33kV which is unusual for the Sydney CBD as it is normally 11kV.
But one of the biggest innovations at the site is the LED lighting installation.
Spies said LED wasn’t where the journey started. The plan was for a traditional T5 fluorescent installation.
He said LED lighting is not a new technolgy but its ability to be used in office buildings over time is yet to be proven.
“LED fittings will become the standard for commercial fittings going forward. This installation has set a benchmark for what is possible,” he said.
“Overall it cost more, but the benefits outweigh the cost.”
There are also vertical fins on parts of the outside of the building to provide shading.
Spies said modelling those fins and the impact they had on performance was hard work.
“We had to use a number of different software package to validate our answers to ensure the solution and cooling capacity we allowed for was sufficient.
“We had to optimise the facade and provide a solution that need less airconditioning before we even started.”