Artificial intelligence, cloud platforms, and high-performance computing are pushing data centres toward unprecedented densities. In response, operators are adopting direct-to-chip (D2C) liquid cooling, a method that delivers coolant directly to processors to maximise heat removal. Water transports 3,500 times more heat from a CPU or GPU than air and has 25 times the thermal conductivity. This makes water a far more efficient medium and positions it at the centre of next-generation cooling performance and sustainability. For mission-critical facilities, the balance between energy and water is fundamental to reliability and efficiency.
Historically, the industry focused on power usage effectiveness (PUE) as the main efficiency metric, with water usage effectiveness (WUE) later introduced to account for evaporative and adiabatic cooling. As liquid cooling becomes standard, the link between energy and water performance is even more critical. Heat transfers from the IT loop to the facility loop and ultimately to the atmosphere via evaporative systems. Any inefficiency in this chain affects the entire system. Poor water quality increases thermal resistance, pumping power, and energy use. Properly treated water improves flow and heat exchange, reducing both power and water consumption. These resources are no longer separate. Optimising one requires optimising the other.
D2C cooling is not just a technological advancement; it represents a shift in how data centres manage the energy-water nexus
Experience across multiple data centres has shown that water quality directly impacts both cooling efficiency and sustainability. In one facility, addressing scale and deposition in cooling systems led to significant improvements in heat transfer efficiency and measurable cost savings. In others, microbial control measures such as reducing Legionella risk have been critical to maintaining system cleanliness and reliability. Broad evaluations across facilities have further demonstrated that improving water chemistry can simultaneously reduce power consumption and conserve millions of gallons of water annually. These lessons are directly applicable in D2C systems that place even greater demands on water performance.
D2C systems are designed around high-density processors and narrow distribution channels, which demand tighter water quality specifications than traditional tower systems. Even minor contamination with silica, iron, or biological material can obstruct cold plate passages, leading to local hot spots, processor throttling, or even failure. Engineering design now extends beyond manifolds and heat exchangers into water chemistry, monitoring, and maintenance protocols.
Maintaining stable operation requires online monitoring of corrosion, bioactivity, and particulates, along with filtration capable of maintaining ultra-low-diameter suspended solids. Chemical treatments must be precisely dosed via automated feed control systems (probes/controllers), often at lower levels than tower systems, but with greater accuracy.
D2C cooling is not just a technological advancement; it represents a shift in how data centres manage the energy-water nexus. Operators who integrate water treatment, monitoring, and control into system design and operation will achieve greater reliability, efficiency, and sustainability.
As new generations of cooling hardware are introduced, consulting engineers have begun embedding water quality requirements into the design phase. Startup cleaning, monitoring sensors, and service partnerships are now being written into specifications as standard practice.
Field experience across hyperscale, colocation, and research facilities shows that D2C systems thrive when water and energy management are engineered as a unified strategy. The next generation of data centres will be defined not only by compute density, but by how intelligently they balance the intertwined demands of energy and water.