Superior Stirling engine technology and performance you can trust to protect your precious biological samples

The biological materials stored in ULT laboratory freezers are incredibly valuable. And yet, researchers have trusted their priceless samples to failure-prone compressor-based technology for decades. Now there is a field-proven, cost-competitive alternative–the free-piston Stirling engine. With only two, non-wearing moving parts, our freezers offer a significant advancement in cooling technology. It’s simply a more reliable system design.


Why compressors fail

  • Moving parts wear out
  • Up to 24 moving parts to fail
  • Oil lubrication management
  • Compressor valves
  • Start-stop operation
  • On-off operation – surge currents

The Stirling solution

  • Don’t wear out – gas bearings
  • Only 2 moving parts
  • No oil
  • No valves
  • Continuous operation with 100% adaptive control
  • No surge currents

Some in our industry have suggested that an ultra-low temperature freezer has to compromise reliability and performance to save energy. Nothing could be further from the truth with Stirling Ultracold. More than 10,000 Stirling engines have been incorporated into life science, university, biotech and pharmaceutical laboratory freezer equipment, including ULT freezers operating in over 300 research facilities. Stirling Ultracold’s technology has even been used by NASA on the Space Shuttle and continues to cool instruments on the RHESSI satellite.

Industry’s Best Performance and Cold Integrity

With our innovative free-piston Stirling engine and unique modulated cooling technology, Stirling ultra-low freezers deliver unequaled temperature stability and uniformity in real-world operation. The SU780XLE’s remarkable temperature uniformity and stability have been confirmed by industry-standard test procedures using the EPA ENERGY STAR® Final Test Method reporting format.

Revolutionary Ultra-Low Temperature Freezers

  • Lowest energy consumption
  • ± 1°C temperature stability in steady-state operation
  • 100% adaptive control, enabling faster temperature pull-down and door opening recovery
  • Most storage volume per square foot of floor space
  • Plugs into any outlet worldwide, including standard 110V
  • Slowest warm-up time
  • Modulated cooling, eliminates on/off cycling, improves reliability and quality of cold
  • Widest cooling temperate range, -20°C to -86°C


Industry-Leading Warranty

We understand how important ultra-low temperature storage reliability is to your research process. That’s why we cover our SU780XLE and SU105UE freezers with a limited warranty (U.S.A) that includes:

  • Two-year warranty for materials and labor*
  • Seven-year free-piston Stirling engine and thermosiphon parts
  • Extended warranty options

Keeping your Samples Safer than Ever