CHILLERS | DATA CENTRE UPGRADE To stabilise the plant equipment, HPF built a supportive platform that could bear more than 300 tonnes At all stages of development, N+1 redundancy was achieved and maintained. The company wanted to sustain an Uptime Institute (UTI) Tier III classification for its data centre, making it concurrently maintainable. This allows for planned maintenance of power and cooling systems tobe carried out without disrupting the operation of the data centre. Now that the upgrade is complete, DCSG has control of its own system, and the landlords system will only be used in the event of critical failure. Generators were placed on top of each other Challenges Unlike in the UK and Europe, where data centres are usually located in large, open warehouses, the high cost of land in Singapore and other parts of Asia means floor space is extremely limited. So Hurley Palmer Flatt had to think vertically. The need to work within the existing floor space of the chiller plant at DCSGs data centre underpinned many of Hurley Palmer Flatts solutions, which were supported by Revit 3D BIM software. There were also instructions not to alter floor-space ratios or interfere with traffic flow on site. The contractor resolved all the clashes on Revit during the development of the drawings. For example, it adjusted the structure framing positions to allow room for the chilled water piping. Another challenge was to level out a sloped ground surface. To The tank for make-up water, sourced from highgrade reclaimed water produced in Singapore stabilise the plant equipment, Hurley Palmer Flatt built a supportive platform that could bear more than 300 tonnes. This would also accommodate future chillers. The platform was a significant feat of civic construction. Rather than build a utility bridge over the driveway on site which may have presented traffic-height restrictions HurleyPalmer Flatt built all connections into an underground trench. Existing chilled water piping infrastructure was used on site with modifications to supply the two new chiller plants, offering cost savings to DCSG. The company also installed a pump on the ground floor, stacking the cooling tower and condensing water heaters on top of it. The chilled water cooler and condenser were fitted in the space between the heaters, and the cooling towers stacked on top. Generators were also placed on top of each other, and the second storey of the chiller plant went as high as six metres. Recycled water was used for the cooling tower make-up water. The source was NEWater high-grade, reclaimed water produced in Singapore from treated used water, which is further purified using advanced membrane technologies and ultraviolet disinfection. To minimise disruption on subsequent stages, all the foundations, with anchorage fittings for equipment, were constructed as part of stage one. This negates the need to bring intrusive piling equipment back on site for future expansions. Hurley Palmer Flatt then installed four 25,000-litre underground diesel-storage tanks, which will help power the whole operation for40 hours continually. Finally, a new substation was built behind the car parkto support the upgrade, thereby providing two sources of power. There is no operational data available at present as, initially, the chiller is meant to operate as backup to the landlords supply. However, both DCSG and the current outsource company operating the plant say the new chiller is efficient and quiet. CJ M ICHAEL TANG is technical director at Hurley Palmer Flatt 48 June 2019 www.cibsejournal.com CIBSE Jun19 pp47-48 DCSG chiller.indd 48 24/05/2019 19:01