It’s the latest trend: Waterless cooling! And why not? Data centers consume a lot of water (and electricity). Even saying the words, “waterless cooling” sounds so appealing, especially to communities where water scarcity is a concern. Waterless cooling, however, is often erroneously presented as a straightforward way to eliminate water-related risks, but the reality involves much more important tradeoffs.
Dry coolers and air-cooled systems can significantly reduce or even eliminate onsite water consumption, making them attractive in water-scarce regions. However, the reduction in water use comes at a cost. No matter how the cookie crumbles, it’s going to cost more. Air coolers are more expensive to build, other forms of cooling come with bigger electric bills, particularly during periods of elevated ambient temperatures. Refrigerants and exotic coolants also come with an increased risk of LTIs and unplanned (and unwanted) environmental releases—and all the bad press that goes with them.
This increased energy use has broader implications. Depending on the local power grid’s energy mix, higher electricity consumption can indirectly increase overall water use—especially in regions where power generation relies on water-intensive processes. It can also raise greenhouse gas emissions, offsetting some of the environmental benefits gained from reducing onsite water use. As a result, the core consideration is not simply whether a system uses water directly, but how total water, energy, and environmental burdens shift across the full lifecycle of operation.
If this sounds like a damned-if-you-do, damned-if-you-don’t situation, you should check out our Water Stewardship Course. There is a balance between water footprint, energy consumption, waste minimization, GHG emissions, capital costs, and operational expenses. Every site has its own unique balance, but you can’t take from one without affecting one or more of the others.
References:
Alkrush, A. A., Salem, M. S., Abdelrehim, O., & Hegazi, A. A. (2024). Data centers cooling: A critical review of techniques, challenges, and energy saving solutions. International Journal of Refrigeration, 160, 246–262. https://www.sciencedirect.com/science/article/pii/S0140700724000458
American Society of Heating, Refrigerating and Air-Conditioning Engineers. (2021). Thermal guidelines for data processing environments (5th ed.). ASHRAE.
Lei, N., Lu, J., Shehabi, A., & Masanet, E. (2025). The water use of data center workloads: A review and assessment of key determinants. Resources, Conservation and Recycling, 219, 108310. https://doi.org/10.1016/j.resconrec.2025.108310
Mytton, D. (2021). Data centre water consumption. npj Clean Water, 4, Article 11. https://doi.org/10.1038/s41545-021-00101-w
National Renewable Energy Laboratory. (2024). Data center best practices for energy and water performance. NREL. https://www.energy.gov/sites/default/files/2024-07/best-practice-guide-data-center-design_0.pdf
Ristic, B., Madani, K., & Makuch, Z. (2015). The water footprint of data centers. Sustainability, 7(8), 11260–11284. https://doi.org/10.3390/su70811260
Siddik, M. A. B., Shehabi, A., & Marston, L. (2021). The environmental footprint of data centers in the United States. Environmental Research Letters, 16(6), 064017. https://doi.org/10.1088/1748-9326/abfba1
UNESCO. (2024). The United Nations world water development report 2024: Water for prosperity and peace. UNESCO.