June 24, 2024 in Advisory Notes
Mould in Buildings and HVAC Systems
Mould plays an important role in the natural environment as a break-down mechanism for dead organic matter. In the built environment, it is an unwante...
Western Sydney Stadium - Bankwest Stadium
A new 30,000-seat sports stadium in Parramatta is bringing rugby league, union and soccer fans in Sydney’s west even closer to the action.
A key role was played by A.G. Coombs in the construction of the new $360 million Western Sydney Stadium, now known as Bankwest Stadium.
Part of the NSW Government’s Stadia Strategy that seeks to improve sporting infrastructure across the State, the new stadium replaces the former Parramatta Stadium while increasing spectator capacity by 10,000.
Designed and built by a consortium led by Lendlease and designed by Populous Architects, Bankwest Stadium offers modern corporate hospitality facilities, including Australia’s first continuous suite deck and a new conferencing and banqueting centre. It also features the steepest grandstands in the country, designed to bring fans closer to the action and amplify the noise of the crowd. The acoustics are further enhanced by the specially-designed roof.
A.G. Coombs’ early engagement as design & construct mechanical services contractor in mid-2016 afforded the project team the opportunity to explore a range of solutions, as well as influence final architectural and structural design decisions.
By exploring alternate mechanical services design paths, the aesthetic appeal of the stadium design was maintained while opportunities to reduce cost were identified.
For example, the A.G. Coombs Group’s experience in data centre CFD modelling was applied to validate alternate design concepts. The discharge of kitchen exhaust under the fabric roof and the thermal load on the stadium’s electric substation were two problems for which CFD modelling was used to develop solutions.
The resulting substation design removed the need for the rigorous mechanical ventilation requirements set out by the energy provider and will influence similar designs in the future.
The project’s ambitions of achieving a Leadership in Energy and Environmental Design (LEED) Gold certification underpinned many of the mechanical services design decisions and led A.G. Coombs to perform life cycle cost scenarios on the possible system solutions.
Life cycle analysis showed that because of the sporadic use of the air-conditioned corporate facilities within the stadium two 1150kW air-cooled chillers in a primary only pumping arrangement in conjunction with two 505kW gas-fired condensing hot water generators was the most cost effective arrangement. This system provides chilled water and heating hot water to the air handling units (AHUs) and fan coil units (FCUs) serving the five floors of the western stand.
Selected with 65 per cent spare capacity on the calculated design day load, the air-cooled chillers were deemed to provide optimum performance over the 50-year life cycle of the stadium. High efficiency, variable speed pumps with N+1 redundancy were also selected for both cooling and heating pumping systems.
The HVAC design serving the air-conditioned spaces of the western stand largely consist of variable flow AHUs serving variable air volume (VAV) terminal units to provide local temperature control and thermal zoning. The use of larger AHUs afforded the benefits of economy cycles and CO2 control, reducing energy consumption and helping to assure indoor air quality. Function suites are served by a VAV system that can be disabled when the spaces are not occupied.
On non-event days when the total demand on the chilled water system is low, the large thermal inertia of the system is utilised to condition spaces such as offices or preparation kitchens with minimal chiller plant activation required. This design has avoided any requirement for a low-load chiller.
Distributed FCUs serve a variety of other spaces in the western stand that experience different usage profiles, including satellite kitchens, stadium office spaces and the atrium. A number of smaller, self-contained spaces located throughout the eastern, northern and southern stands are served by a mix of package units, split systems and ventilation fans.
As the lead contractor for services coordination, clash reporting and building information model management, A.G. Coombs worked to an accelerated construction program that saw the project completed on time and under budget by late 2018.
Four months later, the stadium held its first sporting event with a clash between NRL teams Parramatta Eels and West Tigers.
