The Chillers on the Roof — Datacenter HVAC Oligopoly
The CDU passes the heat from the rack to the chilled-water loop. Something has to chill that water. That "something" is a giant rooftop chiller — a market dominated by a tight oligopoly.
A liquid-cooled AI rack still has to reject heat somewhere . The CDU passes warm water out of the rack into a building-level chilled-water loop, and that loop is ultimately cooled by a large commercial chiller on the roof or in a mechanical yard. These chillers are essentially refrigerators the size of a shipping container. The category is dominated by a tight oligopoly: Trane, Carrier, Johnson Controls, Daikin, and Lennox — plus Modine, which spent the last 18 months pivoting from auto radiators into datacenter cooling and just signed a $4B hyperscaler chiller long-term agreement. Carrier reported datacenter HVAC orders +500% in Q1 2026.
Five companies, big factories, multi-year lead times, and a single hyperscaler can absorb a year of capacity with one signature. Modine's $4B LTA shows how a single deal moves the needle.
5 names on the watchlist
~30% share of large commercial chillers. The chillers that produce the cold water feeding liquid-cooling loops.
Makes giant commercial chillers that produce the cold water feeding liquid-cooling loops. ~30% share of large commercial chillers. The market leader. Datacenter exposure was rounding error two years ago and is now growing 20%+ YoY.
Pivoted from auto radiators to datacenter cooling. Signed $4B hyperscaler chiller long-term agreement. FY26 record sales.
Old-line auto-radiator company that pivoted from automotive to datacenter cooling over the past 24 months , and now ships large chillers to hyperscalers. Signed a $4B hyperscaler chiller long-term agreement — transformative for a sub-$10B market cap. FY26 record sales. The most asymmetric way to play the chiller cycle but the highest beta — execution and customer concentration risks are real.
Datacenter HVAC orders +500% in Q1 2026. Carrier + Viessmann (heat pumps) + datacenter ramping.
UTC spinoff focused on HVAC and refrigeration. Datacenter HVAC orders +500% per Q1 2026 commentary. Diversified across residential, commercial, and refrigeration. The most leveraged of the broad HVAC names to the datacenter wave — but less pure-play than Trane.
Diversified HVAC + building controls. OpenBlue software adds a recurring-revenue layer.
Diversified building-tech leader. HVAC + fire + security + building controls. The OpenBlue software platform is a unique recurring-revenue moat. Datacenter chiller wins growing but less concentrated than Trane.
Global #1 HVAC by revenue. Elliott activist stake disclosed May 2026.
Global #1 HVAC manufacturer. Less datacenter-concentrated than the US names but a long-cycle quality compounder. Elliott Management disclosed an activist stake in May 2026 — could force a US listing or capital-return acceleration. Japanese listing complicates US institutional ownership.
- GMInsights, Dell'Oro · 2024–2026