European 1MW Rack - HDINI

Author: Luis Castrillo, Senior Technologist, Castrol; Jon Summers, Scientific Leader in Data Centers, RISE Collection: 2026-OCP-EMEA-Summit-Cooling-Environments-And-Liquid-Cooling

Summary

The H-DINI project (High Density Infrastructure for Next-generation Infrastructure) is a Vinnova (Sweden's Innovation Agency)-funded research initiative led by RISE (Research Institutes of Sweden) with a broad consortium of Swedish and European industrial partners. The project's objective is to design, build, and demonstrate a 1 MW single-rack computing platform by H2 2028, holistically optimizing for both high-density compute and energy efficiency including thermal energy recovery. The project was motivated by two converging trends: AI training compute growing at 5× per year since 2020 (from epoch.ai data), while hardware compute performance scales at only ~1.4× per year, creating a massive infrastructure gap that drives further data center buildout; and Sweden's national 6G agenda requiring pervasive, dense, energy-efficient compute infrastructure from cloud to edge.

The cooling strategy is a hybrid liquid approach combining single-phase direct-to-chip (DTC) cooling with single-phase immersion cooling deployed simultaneously in the same rack. RISE has developed custom chip load emulators (up to 2 kW per device, temperature-controllable) to emulate next-generation compute without access to actual next-gen silicon. A proof-of-concept test rig — a 6U tank with a 30 kW heat exchanger — has been built to validate the hybrid cooling architecture at small scale before scaling to the full 1 MW system. The project emphasizes the full thermal stack from silicon junction through TIM1, IHS, TIM2, cold plate, CDU, and heat rejection unit, with a key goal of maximizing outlet coolant temperature to enable heat reuse in district heating or industrial applications. Final demonstration is planned for H2 2028 at the RISE ICE data center (an OCP Experience Center).