CALYOS

Belgium | NATO DIANA Energy & Power 2026

Passive two-phase cooling that cuts data center cooling energy by 50% with zero moving parts.

Founded: 2012
Team: 20-30
Funding: EUR 36.7M total (incl. EUR 4M from existing shareholders 2025)
Website: https://calyos-tm.com

DIANA Status

NATO DIANA 2026 Cohort

Technology

CALYOS builds passive two-phase cooling systems derived from satellite thermal management technology (Euro Heat Pipes heritage). Their systems use the latent heat of vaporization to transfer heat without pumps, compressors, or fans.

Key Differentiators

Zero moving parts (no pumps, fans, or compressors) means silent, vibration-free, maintenance-free operation. Up to 50% reduction in cooling energy vs. traditional CRAC/CRAH systems. Works in extreme conditions: dust, vibration, temperature extremes. Space heritage gives unmatched reliability data. Unlike immersion cooling, requires no special fluids or tank infrastructure.

Data Center Value Proposition

Cooling consumes 30-40% of total data center energy. With AI workloads pushing rack densities to 40-100 kW/rack, traditional air cooling is hitting physical limits. CALYOS eliminates the cooling energy penalty entirely for the heat transport loop, and their passive systems scale linearly with rack count without the compounding inefficiencies of chilled water plants.

Cost / ROI

50% reduction in cooling OPEX (electricity). Elimination of water consumption (critical in water-stressed regions -- saves ~1.8L per kWh of IT load). Zero maintenance cost for cooling loop. Higher rack density in same footprint = better $/kW of deployed compute. Payback typically 2-3 years vs. traditional cooling CAPEX.

Technology Readiness

TRL 7-8 -- Demonstrated at BEDEX 2026 for ruggedized/tactical military electronics. Commercial data center deployments in progress.

Summary

CALYOS delivers passive two-phase cooling for data centers, derived from 30 years of satellite thermal management. Zero moving parts, zero water, zero maintenance. Cuts cooling energy by 50%. Selected by NATO DIANA from 400 applicants for mission-critical data center cooling. Works from edge to hyperscale, 40 kW/rack today scaling to 100 kW. Payback in 2-3 years on energy savings alone.

Contact: info@diana.nato.int
Prepared by: NATO DIANA | NATO DIANA Business Development
Date: March 2026 | DCD-NY Edition