As global F-Gas and REACH regulations continue to tighten, refrigerant selection has become a strategic decision that affects not only performance but also compliance and sustainability.
Within Clivet’s product strategy, R1234ze has emerged as the preferred choice across chillers and heat pumps—offering strong efficiency, low environmental impact, and long-term regulatory security compared with R1233zd.

Performance and Efficiency 

R1234ze operates at slightly higher pressure levels than R1233zd, allowing smaller, more efficient compressor designs.
This translates to:

• Compact unit footprints, saving valuable plantroom space.
• Simpler service and installation, due to smaller component sizes.
• Improved Seasonal COP and IPLV when operating within the typical 5–10 °C chilled-water range.

These advantages make R1234ze an excellent fit for scroll, screw and magnetic bearing chillers configurations where flexibility, efficiency, and space optimisation are key.

Regulatory and Environmental Context 

Screen filters use a fine wire mesh screen, and feature a self-cleaning mechanism that automatically and effectively backwashes the fine screen mesh. These filters operate on line pressure, and begin to self-clean when a preset differential pressure across the unit is reached.

Note: The diagram below illustrates refrigerant atmospheric degradation and PFAS emission pathways — not mechanical filtration systems.

Reach Regulation on PFAS

Application Differences

R1233zd is traditionally used in centrifugal chillers, which serve very large capacity applications.
R1234ze, however, suits screw and scroll chillers, making it ideal for modular and multi-combination systems such as Clivet’s SpinChiller 4, ScrewLine 4-i, and Magboast Magnetic Bearing Chillers ranges.
This flexibility supports diverse building types—from universities and hospitals to data centres—where energy efficiency and footprint matter most.

Sustainability and Future Compliance 

Clivet’s refrigerant roadmap combines R1234ze and R290 (propane) to achieve both sustainability and performance goals.
This approach aligns with:

• EU F-Gas phase-down targets,
• REACH PFAS reduction initiatives, and
• The company’s broader aim of delivering energy-efficient, low-impact HVAC solutions.

With upcoming bans and carbon-equivalent quotas tightening, R1234ze’s extremely low GWP and partial PFAS-free composition position it as the most future-proof choice for long-term operations.

Summary

While both R1233zd and R1234ze deliver strong performance, the balance of efficiency, regulatory security, and sustainability clearly favours R1234ze.
For organisations investing in long-life HVAC assets, selecting R1234ze ensures compliance with current and forthcoming environmental standards while maintaining excellent operational performance.