NextDC enables business transformation through innovative data center outsourcing solutions, connectivity services, and infrastructure management software. It provides enterprise-class colocation services to local and international organizations. In July 2012, its M1 Melbourne data center — a 15-MW hyperscale colocation facility — went live. NextDC is committed to sustainability and renewable energy, so it was no surprise when the M1 data center received a 4.5-star rating from National Australian Built Environment Rating Systems (NABERS) in 2016 for incredible building performance. The rating was largely reflective of NextDC’s decision to install Smardt Chillers using Danfoss Turbocor oil-free compressor technology. But, that wasn’t enough. NextDC improved its systems even more, receiving a 5-star NABERS rating in 2019. The M1 data center became the first to ever receive five stars in Australia. Because of the company’s reputation, maintaining and continuing sustainable, efficient systems is essential to upholding its core business values and maintaining its 100% uptime guarantee.

Test for the Best

NextDC consulted with the Smardt Chiller Group, a longtime OEM partner of Danfoss, to further improve the efficiency of the cooling system. In 2016, three additional Smardt chillers were added to accommodate expansion and maintain maximum efficiency at the M1 Facility. In applications like data centers, cooling systems typically have a higher number of run hours than in office buildings and schools. Therefore, efficiency improvements in cooling systems can create major energy savings for data centers. In recent years, data centers have been utilizing various technologies to cool equipment in the most efficient way possible. Further, they are pushing the operating envelope in the server rooms by increasing temperatures. This enables chillers to consume less power but also challenges the compressor operating map. In response, Smardt collaborated with Danfoss to expand the operating map of the oil-free Danfoss Turbocor compressors in order to allow them to operate at higher water temperatures while enabling operation at lower ambient conditions. Compressors operating in these two areas — high chilled-water temperatures and low ambient conditions — run at low compression ratios or “low lift.” Operation in this area offers significant energy savings but requires some changes to the compressor. Smardt and Danfoss engineers overcame these challenges by developing a technology that implements software changes and other improvements needed to allow the oil-free centrifugal Turbocor compressor to operate at optimal efficiency in low-lift conditions.

Low Lift, High Reward

Smardt piloted the low-lift configuration, SmardtLift, with NextDC, which was installed on one of the Smardt chillers at the M1 data center facility. The pilot proved the chiller could run efficiently during low-lift scenarios, meaning it will activate when the ambient temperature of the data center is within an optimum threshold of what the cooling system requires. This method significantly cuts the energy costs of the chillers — by 31% (depending on the ambient conditions). This validation of savings paves the way for upgrading the remaining chillers and creates even greater savings for the facility as a whole. Low-lift operation produces the highest efficiency for oil-free chillers. Oil-free chillers also mean there is no performance degradation over time. The Danfoss Turbocor compressor also supports the data center’s 100% uptime guarantee requirements with its configuration and offers a 30-second restart. The solution has performed so well at the M1 Melbourne plant that NextDC has decided to roll out the SmardtLift across its entire fleet of data centers. Who knew that the trick to improving the most well-oiled machine was a customized oil-free chiller?