Google has published the design for Brazos, a rack-mounted cooling sidecar that lets liquid-cooled servers run inside data halls built for air. The system is generally available. No pricing has been disclosed.
On supply, the company writes: "Brazos is generally available, and our manufacturing suppliers are ready to engage the broader industry to market and produce the Google Brazos design." No lead time, list price or named supplier accompanies that statement, and those are the three things a buyer needs before scheduling anything.
Each installation is three modular cooling units plus integrated rack manifolds, rated at a 60 kW nominal thermal load per rack. Every chassis takes 11 Open Units of rack height and mates with Open Compute Project ORv3 racks. Coolant is either deionised water or a 25 percent propylene glycol mixture, and the units run on a 40 to 60 volt DC input that connects directly to standard rack busbars.
The design separates the internal IT liquid loop from the facility water supply, capturing heat at the component level and rejecting it into the hot aisle through liquid-to-air heat exchangers. That separation is what takes the chilled water plumbing out of the project. Installation runs one rack at a time rather than as a hall-wide shutdown.
Deployment comes with a qualifier attached. The announcement states: "This plug-and-play architecture can be rapidly installed in any legacy facility that has sufficient power and standard air handling." A hall short on either electrical capacity or air handling is therefore not a candidate, and neither threshold is quantified.
Serviceability is specified in more detail than most cooling announcements manage. The chassis sit on low-friction slides so components can be reached quickly, and the pumps and fans are hot-swappable field-replaceable units. Certification covers UL, CSA and IEC 62368-1, leak detection and pressure relief valves are built in, and monitoring runs locally through a human-machine interface and remotely over Modbus over TCP.
Where the sidecar sits against current rack density is the harder question. Data Center Richness puts a typical air-cooled rack at 10 to 20 kW and recent NVIDIA Blackwell deployments at roughly 130 kW, which places Brazos comfortably above the first figure and well short of the second. Neither number comes from Google, which has not said how it runs Brazos across its own fleet.
The specifications are due to become public. Google has committed to open-sourcing the technical specifications, design principles and visual assets through industry forums in the coming months, following the route it took with its Project Deschutes coolant distribution unit.
For operators holding halls they cannot re-plumb, Brazos turns a whole-facility retrofit into a per-rack decision, which changes the capital question more than the thermal one. Buyers should press for pricing, lead times and a named supplier before treating general availability as a date they can build a plan around.
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