Water monitoring and treatment firm Ecolab is set to buy liquid cooling vendor CoolIT Systems for $4.75 billion.

The deal is set to close later this year. CoolIT is currently owned by funds managed by investment firm KKR.

Ecolab said CoolIT is likely to generate $550m in sales over the next 12 months, with data center operators around looking to kit out their facilities with liquid cooling solutions suitable for chilling high-density AI racks.

The deal will double the size of Ecolab’s addressable market in the space, from $5 billion to $10 billion, a statement announcing the deal added.

“AI is transforming the demands on data centers, and liquid cooling is one of the critical technologies that makes advanced computing possible,” said Christophe Beck, Ecolab chairman and CEO.

“By bringing together CoolIT’s engineered cooling technologies with Ecolab’s expertise in water, chemistry, and digital service, we can provide our customers a complete cooling solution that improves performance and reliability while reducing water and energy use.

“This acquisition expands our role in serving the AI ecosystem - semiconductor fabs that manufacture chips, power plants that fuel the chips, and data centers that utilize the chips - and positions Ecolab as the partner that the world’s largest technology companies rely on to grow responsibly and sustainably.”

CoolIT designs, engineers, and manufactures advanced liquid cooling solutions for the data center and desktop markets, including its split-flow direct liquid cooling technology

KKR acquired the firm in 2023 for an undisclosed amount, and news that it was looking to sell first emerged earlier this month. The Wall Street Journal was first to report that Ecolab had won the race to purchase the vendor.

Founded in 1923 to sell carpet cleaning products, NYSE-listed Ecolab provides water treatment and monitoring products and services across industries, including food, healthcare, hospitality, and manufacturing.

The company, via its Nalco Water unit, offers 3D TRASAR water monitoring products for cooling water for cooling towers and chillers, and adiabatic cooling to optimize direct evaporative cooling systems. It launched a data center-centric version for liquid cooling in 2025, and launched its own liquid cooling portfolio in November.

The deal continues a spate of M&A activity in the data center cooling space, with the big players in power and keen to bolster their liquid cooling expertise. Major deals announced in the last 12 months include Eaton’s bumper $9.5 billion acquisition of Boyd Thermal, Trane’s purchase of Stellar Energy Digital, and Daikin buying Chilldyne.