Trial / Demo
Leveraging advanced digital twin technology and climate-specific dynamic simulation, IES Consulting delivered measurable efficiency outcomes for a global data centre operator, demonstrating an industry leading PUE of 1.16 and a possible >90% relative reduction in water usage for one existing site.
Faced with the escalating demands of artificial intelligence and high-density computing, a global data centre operator recently partnered with IES Consulting to future-proof its facilities and deliver measurable efficiency outcomes. The client, driven by their sustainability commitments, sought a solution that would not only optimise operational energy efficiency, water use, and reduce carbon emissions, but also ensure resilience in a rapidly evolving regulatory and technological landscape.
IES Consulting responded by firstly developing a comprehensive digital twin of one of the client’s existing facilities, using their proprietary IESVE software. To ensure accuracy in the results, the data hall model was divided into separate cold aisles, server racks, and hot aisles to accurately simulate the hot aisle containment strategy. In contrast to typical approaches, which often see the entire data hall modelled as a single zone, this more advanced modelling approach allowed the team to accurately represent airflow and temperature variations down aisles and across rows, providing a more robust foundation for evaluating alternative operating, retrofit and cooling strategies and reliably determine the overall efficiency of the site.
Data centre operators are always looking for measures they can implement to improve efficiency outcomes, which is where it is important to consider different design options such as bringing in outside air (free cooling), direct or indirect evaporative cooling, dry coolers, and water-side economisers. However, the effectiveness of these approaches depends partly on the local climate, meaning a method that is successful in one region might not be suitable elsewhere.
By leveraging dynamic simulation tailored to the site’s specific climate, IES was able to identify Direct Evaporative Cooling (DEC) as the optimum solution for the cool dry climate of this particular facility based in North America. The analysis demonstrated that DEC could deliver exceptional performance, with mechanical cooling required for only approximately 15% of the year. For the remainder, ambient outdoor air was determined sufficient to maintain ideal conditions.
The broader results of the analysis were compelling. The simulated DEC system achieved a Power Usage Effectiveness (PUE) of 1.16, representing a 16% improvement over conventional air-cooled chillers (PUE 1.38) and demonstrating significantly improved performance than industry benchmarks, which typically target a PUE of 1.2 or less for highly efficient hyperscale facilities. The results also showed a Water Usage Effectiveness (WUE) of just 0.1, a 95% reduction compared to water-cooled alternatives (WUE 2.06). While the WUE for a DEC system is generally expected to be far higher than the systems being compared, the key qualifier is that although the WUE can spike to over 4.5 when in operation, the WUE for this operator’s specific scenario averages lower across the whole year.
As many data centres are now expanding into regions facing water scarcity or increased regulatory constraints, it is crucial that data centre operators evaluate metrics such as PUE and WUE holistically to achieve a comprehensive understanding of their site’s efficiency, ultimately enabling them to enhance operational performance while mitigating overall environmental impact.
These outcomes were validated through a holistic, climate-specific analysis that benchmarked DEC against standard CRAH systems supplied by both water- and air-cooled chillers. The clear comparison of energy and water use (demonstrated in the chart below) provided the client with actionable insights, enabling informed, risk-mitigated decisions about their cooling strategy and supporting their sustainability commitments.
Although both water-cooled chillers and the DEC design require significant amounts of water, it was determined that giving priority to free cooling could cut water usage by over 90% in this climate zone.
While DEC proved highly effective in the cool, dry climate of this particular site, it was important for the client to understand how they may need to adapt their design and cooling strategies for other sites in their portfolio. IES’s dynamic simulation approach was therefore key in enabling broader evaluation of how such systems would perform under varying environmental conditions and climate zones.
For example, in warmer or more humid climates, evaporative cooling may become less effective, with a risk that cold aisle temperatures could exceed recommended thresholds for significant portions of the year. To address this, IES Consulting referenced ASHRAE’s climate zone classifications, which consider factors such as heating and cooling degree days and annual rainfall. By mapping data centre locations and climate zones, the team demonstrated that while DEC systems can consistently meet performance criteria in cooler, drier regions (such as ASHRAE Climate Zone 5B), their suitability diminishes in hotter, more humid areas (such as Climate Zone 2A), where alternative or hybrid cooling strategies may be required. This holistic, climate-aware approach ensures that each facility’s cooling solution is optimised not just for efficiency and sustainability, but also for long-term operational resilience.
Throughout the engagement, IES Consulting’s end-to-end dynamic simulation services delivered value far beyond traditional design approaches. By integrating physics-based modelling, climate data, and a whole-facility approach, the team empowered the client to clearly identify optimum design and retrofit strategies across their data centre portfolio to increase efficiency and enhance operational resilience. The project stands as a testament to the importance of holistic, data-driven analysis in delivering future-ready, high-performance data centres that lead on sustainability and operational excellence.
