R600a Chiller Prototype with Oil-Free Centrifugal Compressor: Danfoss and ENGIE Refrigeration

Danfoss and ENGIE Refrigeration are developing an R600a (isobutane) chiller prototype featuring an oil-free centrifugal compressor on magnetic bearings. The equipment is at the validation stage and is not yet available for commercial sale.

Project and its status

The goal of the joint development is to bring oil-free compressor technology on magnetic bearings into the high-capacity chiller segment using R600a. The prototype combines the new Danfoss Turbocor TNS385 compressor — Danfoss's first oil-free compressor designed specifically for R600a — with a dedicated ENGIE Refrigeration chiller. Both components remain in development and are not commercially available. The compressor was presented at the Chillventa 2026 exhibition.

Adaptation to isobutane and safety

The transition to R600a affected aerodynamics, seals, motor cooling, and the integrated leak-detection system. Magnetic bearings eliminate oil lubrication of the shaft. After laboratory testing, the compressor is being evaluated within the chiller for joint verification of performance, integration, control, and safety. The system is equipped with automatic protections and safe shutdowns designed for operation with an A3-class refrigerant.

Preliminary specifications

According to preliminary data, the cooling capacity is approximately 385 kW under specified conditions for air-conditioning systems in large buildings; the value is still subject to validation. The energy-efficiency figure will be published after validation is complete.

Timeline

Danfoss plans a controlled market introduction of the compressor in 2027, subject to successful completion of all checks. The launch date for the full chiller has not been announced.

The project represents a step toward applying R600a in high-capacity chillers with oil-free centrifugal compressors; actual performance and efficiency will be confirmed upon completion of prototype validation.

Source: ZeroSottoZero.