A2L Refrigerants for Data Centers: How STULZ Meets EU F-Gas 2024

The EU F-Gas Regulation 573/2024 is reshaping how data centers are cooled. Operators must shift to low-GWP refrigerants without compromising uptime or safety. A2L refrigerants, combined with engineered containment and detection, are the practical path forward. Softprom is the official distributor of STULZ.

What was announced

STULZ has detailed its engineering approach for data center cooling units operating with A2L refrigerants (such as R1234ze, R454B, R32 and R454C) under the new EU F-Gas Regulation 573/2024, which accelerates the HFC phase-down with a full phase-out target by 2050.

Key regulatory milestones impacting data center cooling include: chillers above 12 kW must use F-Gas with GWP below 750 from 01/01/2027; monoblock air conditioners between 12 and 50 kW must use GWP below 150 from 01/01/2027; and units above 50 kW follow from 01/01/2030. Chillers and monoblocks up to 12 kW move to GWP below 150 in 2027 and to no F-Gas by 01/01/2032.

Why this matters

For CIOs, data center operators and procurement leaders, the transition is not a simple refrigerant swap. Mildly flammable A2L fluids require redesigned refrigeration circuits, new detection logic and installation rules under EN 378. In parallel, the REACH PFAS discussion creates uncertainty around some HFOs, making vendor roadmaps and compliance evidence a core selection criterion.

STULZ expects mission-critical cooling solutions to be treated as Ban with Temporary Exceptions, securing normal product-lifecycle operation while the legal framework is finalized by the European Commission and member states.

Technical details

• Standard compliance: A2L systems designed, manufactured and tested per EN 378-1-3 as permanently technically leak-tight, confirmed by Declaration of Conformity.
• Monoblock leak prevention: hermetically sealed circuit, minimum detachable connections, valve caps and vibration dampers on hot gas lines.
• Ignition control: sealed electrical panel; optional heaters limited to 100K below refrigerant ignition point.
• Detection and alarm: at 10% LFL the evaporator fan accelerates to expel refrigerant and other loads shut down; at 20% LFL the unit is disconnected from mains. A separate 230V AC emergency line feeds the detector.
• Outdoor chillers: redundant ventilation of compressor compartments; ground-level detector in low-temperature units (down to -40°C OAT) triggers shutdown at 25% LFL; internal UPS and 230V AC emergency line for safety components.
• Installation rules: charge per circuit limited by EN 378 room classification; outdoor placement preferred; defined safety zones without ignition sources; safety valves discharged to open air; leak test per EN 378-2 §6.3.4 before commissioning.

FAQ

What is an A2L refrigerant and why is it used in data centers?

A2L refrigerants are mildly flammable fluids with low Global Warming Potential. They balance thermodynamic efficiency and compliance with EU F-Gas 573/2024, making them the leading option for new data center cooling units.

Which EN standard governs A2L cooling unit design and installation?

EN 378 (parts 1-3) defines design, materials, leak-tightness and installation requirements. STULZ A2L units are built and tested to be permanently technically leak-tight within this standard.

How does STULZ mitigate flammability risk in A2L chillers?

STULZ combines hermetic circuits, sealed electrical panels, redundant ventilation, multi-threshold refrigerant detection (10%, 20%, 25% LFL) and independent 230V AC emergency power with internal UPS for safety components.

Softprom and STULZ

Softprom is the official distributor of STULZ. Our team supports partners and end customers with sizing, compliance guidance for EU F-Gas 573/2024 and EN 378, and project delivery for mission-critical cooling.

Prepared by the Softprom editorial team based on vendor materials (Softprom DistriFlow). Source: original article.