Why water hygiene is key to data centre efficiency
Author: Joe Peck
AI is driving higher rack densities and increasing thermal loads, placing unprecedented demands on cooling infrastructure. In this exclusive article for DCNN, Gary Nicholls (pictured above), Managing Director of Swiftclean, discusses how proactive water quality management can help data centres maximise the efficient life of critical assets whilst improving operational resilience:
According to the Uptime Institute, average rack power density increased by 38% between 2022 and 2024, largely down to the launch of generative AI to a mainstream audience. We are now on an irreversible trajectory that will continue to compound thermal and energy pressures on data centres and the systems that keep them cool.
As the margin for error shrinks, cooling infrastructure must be managed with the same focus on reliability and resilience as other mission-critical systems. Many data centres are moving to liquid-based cooling systems that can manage rising thermal loads, so water quality plays a fundamental role in maintaining performance and reliability.
With 40% of power usage in a data centre going towards cooling on average, and with water increasingly becoming the primary means of achieving appropriate temperatures, water hygiene is essential and can have a significant impact on operational efficiency and cost.
Water quality: The hidden performance factor
Closed-loop water systems are a critical part of many data centre cooling infrastructures, circulating treated water through chillers, heat exchangers, cooling distribution units, and associated pipework. Although these systems are designed to operate continuously for long periods, they remain vulnerable to gradual deterioration.
Oxygen ingress, depleted corrosion inhibitors, microbiological activity, and the accumulation of suspended solids can all affect water quality over time. The result is a gradual decline in system performance, with corrosion, scale, and fouling reducing heat transfer efficiency and increasing the workload placed on pumps and other components. Equally as important, poor water hygiene can also affect system reliability. Corrosion and contamination can contribute to component degradation, increasing the potential for leaks, equipment damage, and unplanned downtime.
Investing in advanced cooling technology is one part of the solution, but it does not guarantee long-term performance alone. Protecting both efficiency and reliability requires ongoing water testing and treatment to maintain the condition of the water circulating through the system.
Why water sampling matters
Because closed-loop cooling systems often operate quietly in the background, changes in water condition can go unnoticed until cooling performance begins to decline. By this stage, deterioration may already be affecting heat transfer efficiency or the condition of critical components.
Regular water testing for microbial activity provides operators with visibility into system health, allowing changes in water quality to be identified before they become operational issues. Samples can be analysed for key indicators including poor water chemistry and a range of different bacteria.
Water treatment is a lifecycle process
Water Treatment for Closed Heating and Cooling Systems (BG 50/2021) provides best practice guidance for monitoring and maintaining closed circuits, including chilled water systems and closed condenser water systems. The guidance highlights the importance of corrosion control, pH management, dissolved gases, suspended solids, filtration, and microbiological control in maintaining system performance.
BG 50 also reinforces that water treatment is not a one-off activity but a lifecycle process involving commissioning, testing, monitoring, and adjustment throughout the operational life of the system. For mission-critical environments such as data centres, this proactive approach supports equipment protection, energy efficiency, and operational resilience.
Specialist expertise in mission-critical environments
The increasing complexity of data centre infrastructure also places greater demands on those responsible for maintaining cooling systems. In high-security facilities, access to critical infrastructure is tightly controlled and maintenance windows are often limited. Specialist contractors must, therefore, combine technical expertise with robust security procedures and careful planning to ensure essential water treatment and testing activities can be completed efficiently without affecting site security or operational continuity.
As AI continues to increase the demands placed on data centre cooling systems, water hygiene should be treated as an operational risk control measure rather than a routine maintenance activity. Through regular water testing, effective treatment strategies, and proactive maintenance, operators can preserve thermal performance, extend equipment life, and reduce the likelihood of cooling-related downtime.
