A Temporary Chiller Risk Management Strategy at Westmead Hospital

IMG_9558The Situation

Westmead Hospital serves one the largest growing population areas in NSW and is the major teaching hospital for the University of Sydney and one of Australia’s biggest centres for postgraduate training at specialist level in all fields. In anticipation of the extreme heat predicted for Sydney’s summer the team at Westmead Hospital were keen to install a risk management strategy to ensure operations would continue in case of a system overload.

In November, we were contacted by the hospital’s mechanical consultant to work on a risk mitigation solution to meet the demands that summer temperatures will place on the system should the existing chiller system get overloaded. The solution needed to act as an emergency back up to the remaining chillers, and kick in when needed, seamlessly.

The Challenges

With a project of this size, there is always going to be some challenges.

“Firstly, the small footprint with which we had to work with on site meant that craning in equipment and setting it up was tight and needed to be planned for accordingly.” Jonathan Towe, Senior Project Manager, Active Air Rentals, said.

“Secondly, with upwards of 12 truck and semi-trailer movements, a traffic management plan was devised to allow for the transportation of the equipment into place. The plan included traffic controllers at five different points along the four-way intersection, allowing for truck access which also involved a 300m reversing path to access the site.” Jonathan continued.

“Lastly, timing. Active Air Rentals received the go-ahead from Westmead Hospital, on Friday 16 December 2016. From 7 am on Monday 19 December 2016, we had arranged for 12 truck movements and a 130-tonne crane to position equipment. The solution was commissioned by Thursday 22 December 2016. “Job Finished”, Jonathan.

The Solution

Working collaboratively with Westmead Hospital’s Capital Works team, we were able to come up with a solution that would address the challenges and meet the project requirements.

Using the two pre-existing valves from where the main headers connected to the system, we ran 300mm stainless pipework through the wall to the exterior of the building. From there we ran five connections to five chillers with a combined capacity of 3,500 kW. Partnering each chiller was a generator which would require refuelling every few days throughout the running period.

The temporary system was interfaced with Westmead Hospital’s building management system (BMS) allowing for seamless integration and sequencing on and off of the chillers and generators as required.

“The [Active Air] installation team are to congratulated for their assistance in providing excellent service and advice that enabled this critical piece of infrastructure to perform exceptionally during very testing conditions.”

David Dobson, WSLHD Senior Project Manager Capital Works, Program Management Office (PMO)

The temporary solution remained in place through to March.