By Eamonn Ryan
The Green Cooling Summit 2026, hosted by the German Environment Agency (UBA) and GIZ Proklima on behalf of BMUV and BMZ, and facilited by Julika Schmitz, is built around a technically simple but strategically complex problem:
Julika Schmitz, facilitator. © RACA Journal
Why is R290 (propane), a proven high‑efficiency, low‑GWP refrigerant, still struggling to gain a significant share in the room air‑conditioning (RAC) market – and what is needed to make it a standard? This is part one of a two-part series.
This Part 1 sets out the context, technical characteristics, and core deployment challenges of R290 in RAC. It establishes that the main barrier is no longer technological innovation, but scaling and system‑level implementation.
- Summit objective and framing
The summit starts from the premise that R290 RAC technologies already exist and work:
- Commercially available units demonstrate high energy efficiency.
- Direct climate impact is extremely low due to R290’s very low GWP (~3).
- Systems can be engineered to meet stringent safety requirements for A3 (highly flammable) refrigerants.
The guiding questions are therefore:
- What is holding back large‑scale deployment of R290 in RAC?
- Which regulatory, market and technical conditions are missing?
- How can R290 move from niche to standard?
- This reframing shifts the focus from ‘Can R290 work?’ to ‘Why isn’t it scaled yet, and how do we fix that?’
- Technical profile of R290 in RAC
For room air‑conditioning, R290 exhibits a favourable technical profile:
Thermodynamic performance
- Favourable pressure–temperature relationship
- High volumetric cooling capacity
- Strong potential for high COP/EER in optimised system designs
- Climate and environmental performance
- GWP ≈ 3, essentially negligible compared to typical HFCs (for example, R410A, R32)
- Supports deep lifecycle emissions reductions when combined with efficiency gains
- Safety classification
- Classified as A3 (highly flammable)
Requires:
- Compliance with charge‑size limits
- Appropriate equipment design (for example, leak management, ventilation, ignition source control)
- Installation and servicing protocols tailored to flammable refrigerants
Technically, R290 is already capable of delivering efficient, climate‑aligned cooling in RAC, provided that design and safety standards are correctly applied.
- The deployment gap
Despite this technical maturity, R290 remains a minority option in many RAC markets. The summit identifies a deployment gap, driven by:
- Regulatory uncertainty and inertia
- Building codes and safety rules not yet fully adapted to A3 refrigerants
- Legacy standards designed around non‑flammable or lower‑flammability refrigerants
- Market structure and risk perception
- Manufacturers’ reluctance to re‑tool for A3 production
- Perceived legal, safety and reputational risks
- End‑user and authority concerns regarding flammability
- Capacity and infrastructure constraints
- Limited availability of trained technicians for A3 systems
- Need for upgraded tools, procedures and inspection regimes
Part 1 concludes that the primary constraints are framework and capacity related, not inherent to R290’s technical performance.
© RACA Journal
