Bio-based Fluids for European AI Data Centres

Author: David Gyulnazaryan, Executive Consultant, Impleon; Massimiliano Dall'Armellina, Global Sales Development Manager, Frigel Collection: 2026-OCP-EMEA-Summit-Cooling-Environments-And-Liquid-Cooling

Summary

This presentation argues that traditional multi-loop data center cooling architectures waste 30–40% of energy through unnecessary thermal cycling and intermediate heat transfer steps, and that a single-loop design using a bio-based propylene glycol fluid (Bio PDO25) can eliminate these losses while satisfying European heat reuse legislation. The core thesis is that replacing the conventional three-loop design (dry cooler → Eth.glycol at 35–45°C → chiller → facility water at 25–35°C → CDU → PG25 TCS at 35–45°C → cold plate) with a single-loop (dry cooler → Bio PDO25 at 35–45°C → cold plate directly) removes the chiller, CDU, and intermediate pumping systems, cutting infrastructure energy overhead by roughly 30–40%.

The presentation introduces Bio PDO25, developed by Impleon in collaboration with Premiant and Frigel (Italy), as the enabling fluid. Its key advantages over conventional ethylene glycol (EG25) and propylene glycol (PG25) are: non-toxic (unlike EG25), lower viscosity at cold ambient temperatures than PG25 (6.4 cps vs. 7.9 cps at 25°C), and dramatically lower GHG embodied carbon (0.71 kg CO2-eq/kg vs. 2.00 for EG25 and 4.43 for PG25). Foaming performance (<50 ml per ASTM D1881) also exceeds PG25 (<150 ml) and matches EG25 (<150 ml).

Frigel's contribution is a modular multi-mode machine — combining dry cooler, chiller, and heat pump in one unit — that operates across three modes: free cooling (ambient air < 33°C, no compressor), air-cooled chiller mode (ambient > 33°C), and heat export/heat pump mode (producing hot water above 43°C or up to 95°C for district heating connection). This architecture makes the single-loop approach viable for European markets where heat reuse is now legally mandated: France requires 100% waste heat recovery from data centers ≥ 1 MW from January 2026; Germany requires 10% reuse from July 2026, rising to 15% in 2027 and 20% in 2028. The speakers close with a call to action for OCP to develop a TCS single-loop design, OCP AI rack compatibility with this approach, and an OCP bio-PDO based fluid specification.