Pumps, a heat exchanger, filters and controls that circulate the rack’s clean coolant and pass its heat to the building’s water loop.
What does a CDU do?
Cold plates on the GPUs and CPUs carry heat into a technology cooling loop. The coolant distribution unit passes that heat through a liquid-to-liquid heat exchanger to the facility loop, keeps the two loops separate, and controls the rack loop’s pressure, flow and temperature with redundant pumps, filters and leak detection. NVIDIA’s GB200 NVL72 design calls for 120 kW of cooling per rack, and Lenovo’s GB300 NVL72 guide puts about 90% of the rack’s heat into liquid, with supply water as warm as 45 °C. NVIDIA says warmer water can reduce or eliminate the need for mechanical chillers in a wide range of climates.
In-rack, in-row or sidecar?
An in-rack CDU sits at the bottom of one rack and serves only that rack: Kaori’s takes the height of four 1U servers, Delta shows a 4RU 140 kW unit for GB300 NVL72, and Supermicro’s GB300 NVL72 rack carries one of up to 250 kW. In-row CDUs serve many racks from their own cabinet: Delta showed 2.4 MW and 3 MW liquid-to-liquid units in March 2026, Lite-On a 2.1 MW unit, Vertiv’s CoolChip range spans 70 to 2,300 kW, and Modine’s Airedale unit runs from 400 kW to more than 2 MW. Liquid-to-air sidecars, such as Supermicro’s 200 kW unit, suit sites without facility water. The illustrated rack shows an in-rack unit; Lenovo’s guide allows either placement.
Who makes cold plates and CDUs, and who owns them now?
Taiwanese and Chinese thermal specialists document AI liquid-cooling lines: AVC calls 2025 its “Inaugural Year of Liquid Cooling,” Auras shows cold plates, manifolds, quick disconnects and CDUs, Envicool and Delta sell cold plates and CDUs, and SUNON began shipping cold plates in 1H 2026. nVent says it defined a GB200 NVL72 reference architecture with NVIDIA using its CDUs, heat exchangers and manifolds. Industrial groups have acquired specialists: Eaton closed Boyd Thermal on Mar 12, 2026, Ecolab closed CoolIT on July 2, 2026, and Motivair and JetCool now sell as Motivair by Schneider Electric and a Flex company. Those units are reached only through their owners’ shares, and LiquidStack is private. Which supplier cools a given NVL72 rack is not disclosed.
How to research a liquid-cooling company
Place the product in the loop: cold plate, manifold, quick disconnect, in-rack CDU, in-row CDU, sidecar or facility chiller. Each has different makers and scale.
Compare ratings in the same unit: an in-rack CDU is rated in kilowatts for one rack, an in-row CDU in megawatts across many racks.
Separate the evidence: a partner list, a claim of compliance with a reference design, a reference architecture and a named program are different milestones.
Check ownership after the recent deals: Boyd Thermal (Eaton), CoolIT (Ecolab), Motivair (Schneider Electric), JetCool (Flex); AVC consolidates Fositek with a 16.87% holding.
Check revenue mix and governance: servers were 66% of AVC’s Q2 2026 revenue, and Nidec’s shares were designated a Security on Special Alert after a Third-Party Committee reported inappropriate accounting.
Use the list as a starting point: it is curated, not exhaustive, and the model is illustrative, not a bill of materials.
Heat moves from the technology cooling loop through a CDU’s liquid-to-liquid heat exchanger to the facility loop; warmer water can reduce or eliminate mechanical chillers.
Disclosed: nVent’s release says it worked with NVIDIA to define a GB200 NVL72 reference architecture using its CDUs, heat exchangers and manifolds, and quotes NVIDIA.
Disclosed: Delta’s GTC 2026 release and data-center catalog describe power shelves, BBUs, cold plates and CDUs for NVIDIA platforms, including a GB300 NVL72 in-rack CDU; NVIDIA lists Delta among its 800 VDC partners.
Disclosed: Envicool’s H1 2026 report describes its Coolinside cold plates, quick disconnects, manifolds and CDUs and says NVIDIA listed its UQDs among MGX ecosystem partners.
Disclosed: Vertiv’s product page names the PowerDirect 3000 shelf for GB200 and GB300, and its release describes a GB300 NVL72 reference architecture; NVIDIA lists Vertiv among 800 VDC partners.
Disclosed: AVC’s 2025 annual report describes cold plates, CDUs, manifold systems and fans for AI servers, and its Q2 2026 results put servers at 66% of revenue.
Disclosed: Flex’s release describes its 800 VDC Power Rack for NVIDIA Vera Rubin, and its Sept 2026 8-K lists power shelves, PDUs, cold plates, manifolds and CDUs; NVIDIA names Flex as an 800 VDC partner.
Disclosed: Nidec’s Nov 2025 financial statements summary cites water-cooling modules for AI data centers, and its product pages describe data-center CDUs, fans and heat sinks.
Disclosed: Airedale by Modine’s product page lists the 400 kW–2 MW+ CDU, and Modine’s releases report data-center sales and a $4 billion+ capacity agreement.
Partner-disclosed: NVIDIA’s technical blog says the GB300 NVL72 power supply’s energy storage was co-designed with LITEON; Lite-On’s GTC 2026 release covers its 800 VDC power rack, shelves and CDUs.
Disclosed: Eaton’s Q2 2026 10-Q records the Boyd Thermal acquisition, and Boyd’s own pages describe its AI cold plates and CDUs; NVIDIA lists Eaton among 800 VDC partners.
Partner-disclosed: NVIDIA’s Oct 2024 OCP post names Sanyo Denki among Blackwell infrastructure partners; its own releases market a GPU-server fan and a liquid-cooling pump.
Disclosed: Jentech’s Nov 2025 investor conference (MOPS) lists AI servers among the applications of its liquid-cooling modules and heat spreaders; customers unnamed.
Disclosed: Furukawa Electric’s releases and product pages describe the 13,824-count cable, the CW-DFB chip and the ¥55 billion data-center cooling investment.
Also in this study (not publicly listed)
CoolIT Systems Subsidiary of Ecolab (ECL)
Canadian maker of CDUs, cold plates, coldplate loops and rack manifolds, named by NVIDIA among Blackwell partners. Ecolab closed its ~$4.75 billion acquisition on July 2, 2026, so Ecolab (ECL) is the listed owner, proposed as a row.
Cold plates, manifolds and CDUs for AI data centers; acquired by Eaton on Mar 12, 2026 for $9.55 billion net of cash. Boyd’s remaining Engineered Materials business is a separate private company.
Buffalo-based maker of CDUs, ChilledDoor rear-door heat exchangers and cold plates, now sold as Motivair by Schneider Electric; its exposure is through Schneider Electric’s row, not a separate stock.
CDU maker (CDU-1MW; GigaModular CDU up to 14 MW) that says it is designed for AI factories including NVIDIA Vera Rubin and is “backed by” Trane Technologies’ manufacturing and service; whether Trane owns it was not verified, so Trane is not a stand-in.