National Archives of Australia

Awarded the mechanical services contract for the design and construct project by Construction Control, Benmax completed a major refurbishment of the 10,000 sqm archival storage facility located in Mitchell, Canberra.

Constructed in 1981, the government owned building required a significant overhaul to ensure its integrity as a critical climate archival storage facility could be maintained. The facility is responsible for preserving records that reflect Australian history and identity and include paper records, audio-visual records and a digital archive and requires critical climate conditions to minimise temperature and humidity variations across key areas of the building to ensure items are not damaged and do not deteriorate.

Wanting to maintain the exterior facade of the building, the project focused on the removal of the existing roof to make way for the construction of a ‘concrete lid’, as well as a complete refurbishment of the building interior including essential plant and services.

The mechanical system includes air cooled chillers; gas fired boilers; thermal storage tanks; dehumidifiers; humidifiers; AHUs; fume cupboards; computer room air conditioning units; cold storage; as well as various miscellaneous air conditioning and ventilation systems.

A BMCS monitors air quality to help prevent any potential corrosion of the stored items as well as energy usage, alarms and provides the user with diagnostic capability to help keep the facility operation optimised.

The original design for the facility was enhanced by the Benmax team following in-house engineering reviews with agreed changes including:

• Diverting the relief air path to wrap around the storage vaults. This provided a cocoon of conditioned air between the vaults and the façade of the building to help improve stability of the conditions within the vaults.
• Introduction of G3 Lab Accuvalves on the outside and relief air paths to maintain a positive 5Pa vault pressure. The monitoring and adjustment of air flows into and out of the vault by these valves ensures tight control over very low room pressures. The technology incorporated vortex flow measurement with fast acting dampers. This level of control also benefited the overall system stability and maximised mechanical system efficiency.
• Introduction of Seibu Giken dehumidifiers due their high efficiency rotors, ease of maintenance and ceramic heaters that avoid nuisance tripping.
• Boiler flues hidden within an existing stack to maintain a clean building line (this required an innovative prefabrication solution).

“Benmax provided a seamless and comprehensive mechanical design, construction and commissioning service to this critical government facility. The design and practical hands-on experience of the Benmax team was a critical factor in us providing the strict internal climate conditions required for the archive spaces.”

Peter Wright, Director – Construction Control