The new Royal Adelaide Hospital, due to be completed in 2016, will have 800 beds and world class facilities including a helipad sitting atop its south west corner.
While the helipad will assist in patient transportation, it does present one problem. From 20 metres away, helicopters create over 100 decibels of noise (equivalent to being in the front row at a rock concert) which is not very conducive to patient rest.
Facade manufacturer Yuanda Australia has been contracted by builder HYLC Joint Venture to supply the hospital with its external windows (all 70 000 square metres of them). Yuanda's contract states that noise reduction must be considered when choosing glazing materials.
The team from CSIRO’s acoustics lab in Melbourne has been working alongside Yuanda's engineers, measuring the performance of the windows to ensure that the South Australian Government’s stringent sound-proofing requirements are met.
To undertake the measurements, the team custom-built a brick wall between two cavernous sound chambers to hold sample windows. A standardised sound source generated noise in one chamber, while sound intensity and pressure levels were measured on the other side of the glass.
According to CSIRO project leader Dr Christopher Preston, this allowed the CSIRO team to assess how well the glazing would perform when exposed to the noise of a helicopter.
"To ensure that all areas of the hospital meet the sound insulation requirements, a range of different window configurations had to be evaluated," he says. "This meant the brick wall had to be knocked down and rebuilt about a dozen times in order to hold different facade elements."
The results showed that Yuanda's glazing systems would effectively reduce the impact of helicopter noise on patients.
CSIRO's acoustic laboratory is one of the few facilities in Australia equipped to perform the low frequency measurements required for this type of assessment.
By working with companies like Yuanda, Dr Preston says that CSIRO is helping better match building products to the needs of the Australian community.
According to Yuanda engineer Gareth Winstanley, with the testing phase now complete, the glazing is ready for production. "When it is finished the new Royal Adelaide Hospital will be the quietest hospital in the country," he says.
CSIRO's Infrastructure Technologies group is internationally renowned for its work in facade systems, having assessed some of the world's most iconic buildings including the Chanel Ginza building in Tokyo and the Lucas building in Singapore. Locally, the acoustics team has conducted testing for the Sydney Harbour Tunnel, as well as Sydney Airport.