White Rabbit G (WRG) is the largest tri-hull and largest aluminium superyacht in the world. At 84m she is also the largest superyacht to be built in Australia. She was built at Echo Yachts in Henderson and can accommodate up to 30 guests with a crew of 32. White Rabbit even picked up the Best Naval Architecture Award for Displacement Motor Yachts at the Boat International Design & Innovation Awards 2019.
Cool Technology was initially contracted to design the Air-conditioning and ventilation systems for the vessel. Once the design was submitted and approved, we were asked to tender on the manufacture and install the Air Handling and Chilled Water System.
We won the tender and commenced work on the vessel in 2015. The project took over 2 years and consumed over 6,500 Man Hours. The water chiller rack and Seventeen Built-up Fan Coil Units were built in our falsity and delivered to site. Commissioning was commenced at Henderson and completed in Singapore.
The chiller unit consist of four individual refrigeration circuits. Each circuit has a Bitzer Screw compressor, Bitzer sea water condenser and a plate heat exchanger. The package is complete with all operational and safety controls. The compressors have VSD driven providing soft starting and capacity control. The chiller unit are sea water cooled by bronze self- priming pumps, two pumps provided, one 100% standby. The chilled water pump was provided to circulate chilled water to the fan coil units distributed throughout the vessel. A standby pump was also provided.
The Seventeen Built up Air Handling Units were provided as per the equipment schedule. VAV controls were installed for individual owner and guest cabins.The Galley and Lower Deck Fwd cabins were served by individual Fan Coil Units. A Separate fresh air unit was provided to supply air to the crew cabins. The Plant Room & electrical room were served by dedicated Fan Coil Units.
A separate window demister was provided for the fwd wheelhouse windows. Exhaust systems served all toilet areas, dry stores and laundry. A galley exhaust canopy was provided along with supply and exhaust fans and associated fire dampers. Closing devices for all ventilation inlets and outlets were included and remote monitoring of these devices can be by the shipyard.
We calculations the load in accordance with AS1921-1976 and AS1668. Design criteria is based on the following data:
Ambient
Summer: 0ᵒC and 85% RH
Winter: -5ᵒC
On board temperature
Summer: 3ᵒC and 55% RH
Winter: 22ᵒC
Sea water temperature
5ᵒC to 30ᵒC
Outside air
7.5L/s/person or 10% more than exhaust air
Total Loads:
Cooling: 330KW
Heating: 140KW
The major difficulty of this project was that it ran longer than any other ship build we have built before. Access to the separate compartments were restricted and only available when other trades were finished working in them. So, a high degree of cooperation and planning had to go into the project. A separate team of fabricators worked in our facility to manufacture the chiller system prior to delivery to the vessel. Each of the 17 Air Handling Units were unique and had to be designed within a 10mm tolerance to fit into the tight compartment onboard the vessel. These were manufactured individually in our fabricators also.
By far this project was the largest that Cool Technology has ever undertaken. Its complexity of design, installation and standard of finish was of the highest quality. We could not be prouder of the finish product and performance of the system. Our design and engineering team worked hard over a long period to achieve what we think will stand out as the benchmark for boat building for a long time. We learnt many lessons and overcame many difficulties along the way and can now out these experiences to good use on future projects.
