Two ways to reach −80 °C
Most laboratory freezers reach ultra-low temperatures with a cascade compressor system: two or three compressors and a synthetic refrigerant blend. Our free-piston Stirling engine takes a different path — a sealed, oil-free mechanical heat pump driven by a linear motor.
Side-by-side
- Vibration: Stirling cores are balanced and nearly silent (<55 dB); compressors vibrate and transmit micro-motion to shelving.
- Service life: No lubricated moving seals means far fewer wear points in the cold head.
- Power: Both are efficient at steady state, but the Stirling unit's 120 W draw suits battery and vehicle (24 V DC) operation.
- Refrigerant: We use R-170 (ethane), a natural, low-GWP gas; many compressors still rely on high-GWP blends.
Where Stirling wins
For field, mobile and off-grid use, and for any samples sensitive to vibration, the Stirling approach is the stronger choice. For very large stationary archive banks where absolute lowest capital cost dominates, conventional cascade compressors remain common — but they are harder to run on DC power.
The trade-off
Stirling units are a newer platform with a smaller installed base, so local service coverage can be thinner than for legacy compressor brands. We mitigate this with simple, modular cores and OEM support for integrators.