Cooling technology company Nexalus ran an eight-month outdoor field trial of two sealed prototype servers at a telecom site in Arlington, Texas, beginning in December 2024, exposing the units to ambient temperatures ranging from minus 7 degrees Celsius to 40 degrees Celsius with no service visits or component changes. Inside the sealed enclosure, air reached 59 degrees Celsius, yet the company reported no throttling, no instability, and no hardware faults; the only downtime resulted from a site power outage. Because the closed loop returns water above 60 degrees Celsius, Nexalus says heat can be rejected through a dry cooler rather than an evaporative tower, bringing water usage to zero. Modeled with Collen Construction and four engineering partners, the company says a 2.5 megawatt retrofit could convert 310 air-cooled racks at 8 kilowatts each into 100 racks at 25 kilowatts, freeing roughly one-third of the floor plate.
Eliminating evaporative cooling water consumption directly addresses one of the most cited sources of community opposition to data centers, and field validation under real outdoor conditions over eight months provides more concrete performance evidence than laboratory tests alone. If the sealed-server architecture scales commercially, it could allow data centers to be sited in water-stressed regions or near communities where evaporative cooling has been a regulatory obstacle.
Data Center Dynamics' focus on sealed-server immersion or containment cooling as a regulatory and operational enabler is a distinct angle on cooling innovation not duplicated in already-published stories, and the 'license to operate' framing suggests policy relevance.