With state-of-the-art MEP infrastructure and networking equipment, NTT Communications Hong Kong Financial Data Centre Tower 2 (FDC2) is designed to be compliant with the Uptime Institute’s multi-tier requirements up to Tier IV, the highest rating measuring the quality and reliability designed into a data centre.
As the mechanical, electrical, public health, IT and security engineering consultant, Arup worked with the client to devise a number of innovative solutions to help the premium mission critical facility to meet the reliability challenge and achieve energy efficiency and design flexibility.
2 TES tanks using the water stratification principle
4,200 racksultimate capacity
<1.5 power usage effectiveness value
Unique emergency cooling strategy 1
A continuous cooling system is vital to achieve 24/7 non-stop operation of the data centre. To realise FDC2’s promise of 100% uptime, we helped our client to realise a cutting-edge cooling strategy using two thermal energy storage (TES) tanks employing the water stratification principle, the first of its kind in Hong Kong.
Since water density is inversely proportional to temperature, hot and cold water can be completely separated with the hotter, lighter water at the top (with a thermocline separation). The designed cold water temperature and volume can then be secured during the operation at all times and scenarios to feed the data centre cooling system with the return hot water trapped in the upper layer.
In this project, two TES tanks were designed to ensure the hot-cold water separation. Using computational fluid dynamics simulation for verification, we designed the water inlet and outlet diffuser to ensure a steady water flow for the formation of the ‘thermocline’ and water stratification.
Image ©NTT Com Asia Limited
Given the high power demand of the data centre, various cooling approaches were employed to improve energy efficiency and save costs for the client. These include front-flow air handling units, indirect free cooling from the cooling towers in winter, and efficient plant design.
As a result, the annualized power usage effectiveness (PUE) value can achieve below 1.5 at full load condition, compared with the local average of 2.3.
Image ©NTT Com Asia Limited
Designed to be a future-proof facility, FDC2 adopts a modular design, allowing phased capital investment (to reach the ultimate capacity of 4,200 racks) as well as flexibility for end-users to tailor make their solutions in the future with a wide power density ranging from 4kW to 24kW per rack.
This also allows the building to react to changing business requirements and technological advancement in the future with minimum impact on the operation, hence facilitating deployment, saving costs and reducing risks to other operating areas.
BIM as a process
We formulated a fully built BIM model throughout the design life cycle, the first time for the local data centre market. Through this project, BIM has advanced from being a tool to a truly collaborative process, enabling coordinated working, clash reduction, design optimisation and improved efficiency.