The CDUs & Cold Plates — Liquid Cooling at Rack Scale
Every Blackwell and Rubin rack needs a CDU. Vertiv is the de facto leader with a $15B backlog — roughly 12–18 months of forward revenue locked in.
A coolant distribution unit (CDU) is a refrigerator-sized box that sits next to a server rack. It pumps cold liquid (water-glycol or a dielectric fluid) through manifolds, into cold plates that sit on top of every GPU, then back to the CDU where the heat is exchanged with a building-level chilled-water loop. The CDU is the unit-of-work for AI cooling — and it is still in short supply. Per GMInsights, Vertiv held 11.3% data center liquid cooling share in 2025 ; Dell'Oro calls Vertiv and Schneider "virtually tied" as leaders. Vertiv's CoolChip CDUs are the de facto standard for high-density AI deployments. Eaton acquired Boyd Thermal (cold plates) in March 2026 to become immediately competitive.
You cannot ship a Blackwell or Rubin rack without a CDU and cold plates. Vertiv's Q4 2025 book-to-bill was 2.9x and the backlog grew 109% YoY to $15B. Backlogs that big translate into 12–18 months of forward revenue without a single new order.
4 names on the watchlist
Pure-play AI datacenter physical infrastructure. ~75% of revenue from datacenters. $15B+ backlog.
The "Cisco" of physical AI infrastructure. Sells UPS systems, switchgear, racks, CDUs, immersion cooling, and chillers to hyperscalers and colos. ~75% of revenue from datacenters. Q1 2026 revenue $2.65B (+30% YoY); adjusted operating margin 20.8%; Q4 orders +252% YoY; backlog over $15B; FY26 EPS guide $5.97–6.07. Acquired ThermoKey (Mar 2026), Strategic Thermal Labs (Apr 2026), and BMarko Structures (Apr 2026). Investment-grade ratings Feb 2026.
European Vertiv equivalent. UPS, racks, EcoStruxure software. Acquired Motivair (Oct 2024, $850M) for liquid cooling.
European leader in datacenter physical infrastructure. Acquired Motivair Oct 2024 ($850M) for liquid cooling. NVIDIA GB200 reference-design partnership. EcoStruxure software adds a recurring-revenue layer Vertiv doesn't have. Less concentrated than Vertiv but slower-growth. Lower-beta way to play the same secular trend.
Power distribution + cooling. Acquired Boyd Thermal (cold plates) March 2026 — immediately competitive with Vertiv.
Diversified power-management leader. Acquired Boyd Thermal in March 2026 — immediately competitive with Vertiv on cold plates and CDUs. Also a major Sector III (Non-AI Energy) name on the power-distribution side. The most diversified way to play both cooling and grid simultaneously — lower beta, less pure-play.
Schroff (racks) + Erico (electrical) + NVIDIA partnership for rack-scale solutions. Cold plates via CoolIT/Trachte.
Rack-level cooling and electrical-connection specialist. NVIDIA partnership for rack-scale solutions . Cold plates via the CoolIT and Trachte product lines. Smaller, more pure-play than Vertiv on the rack-level cooling segment; less exposure to the big CDU contracts.
- GMInsights, Dell'Oro · 2024–2026