Data centers slow to drop evaporative cooling despite water use

Evaporative cooling remains the dominant method for managing heat in data centers, despite growing concerns over its heavy water consumption. While alternatives like liquid cooling offer greater sustainability, industry adoption has been slow, driven by cost, energy constraints, and scalability challenges.

The technology, which cools facilities by evaporating water through membranes, is energy-efficient but requires millions of gallons of water daily—equivalent to the usage of thousands of households. This demand strains local water supplies, particularly in regions facing shortages, and raises environmental risks from runoff pollution. Yet, evaporative systems persist due to their low operational costs and reliability.

Why evaporative cooling still dominates

Evaporative cooling’s cost advantage is a key factor in its continued use. Installation and operating expenses are significantly lower than those of alternatives like mechanical refrigeration or liquid cooling. For example, evaporative systems cost roughly $0.80 per megawatt-hour of IT load in water expenses, while liquid cooling can require up to $5 million per megawatt for installation—more than double the cost. Retrofitting existing facilities further amplifies these expenses, making operators hesitant to switch.

Energy availability also plays a role. Data centers already face grid constraints, and electricity-intensive cooling methods exacerbate power demands. While water shortages are a concern, they have not yet reached a critical threshold in most regions to justify the higher energy costs of alternatives. Additionally, evaporative systems scale more easily than mechanical refrigeration, which struggles to meet the cooling needs of large facilities.

The rise of liquid cooling

Liquid cooling is the most promising alternative, with adoption projected to reach 50% of new data center installations by 2031. Its efficiency in handling high-density computing, particularly for AI workloads, has accelerated its growth. However, barriers remain: high installation costs, operational complexity, and limited scalability for large deployments. Free cooling—using outdoor air—is another option but is geographically limited to cooler climates.

What’s next for data center cooling

The industry’s shift away from evaporative cooling will likely be gradual. While liquid cooling’s efficiency and sustainability advantages are clear, cost and scalability concerns will keep evaporative systems in use for the foreseeable future. Operators may adopt hybrid approaches, combining evaporative and liquid cooling to balance performance and resource use. Regulatory pressures and water scarcity could also accelerate change, particularly in drought-prone regions.