Laboratories are known for their energy-intensive operations, often requiring round-the-clock use of essential equipment such as fridges and ULT freezers. While there are some simple maintenance practices that can optimize efficiency, it's crucial to consider the long-term costs and energy consumption when selecting a ULT freezer. 

In this article, we explore the Stirling Ultracold SU780XLE ULT freezer, a sustainable solution that excels in energy efficiency, high-capacity storage, superior recovery, and optimal sample preservation.

Why Purchase The Stirling SU780XLE ULT Freezer?

Benefit 1: Excellent Energy Efficiency

Traditional ULT freezers can consume a staggering amount of energy, particularly older models that might consume up to 30 kWh/day when set at -80 °C. In contrast, the SU780XLE ULT freezer offers remarkable energy efficiency, using as little as 6.67 kWh/day at -75 °C and approximately 8.86 kWh/day (set at -80 °C) in typical laboratory conditions.

 The SU780XLE's W/L/Day consumption also stands out, allowing for easy comparison with other freezers. By adjusting the set temperature from -80 °C to -70 °C, users can achieve 25% energy savings, with energy usage dropping to just 6.71 kW/day (or 9.00 W/L/Day).

Benefit 2: High-Capacity Storage and Space Efficiency

Unlike conventional compressor-based cooling systems, the SU780XLE ULT freezer incorporates a patented Stirling engine, which optimizes space utilization. With the largest m3 storage capacity per m2 of floor space available on the market, the SU780XLE offers a usable capacity of 47% relative to its footprint. 

This means laboratories can store more samples before needing additional units. Additionally, the SU780XLE's design allows for closer placement of multiple freezers due to its smaller clearance for door swing and upper-side air venting. These features enable organizations to maximize their lab space and create high-density storage environments.

Benefit 3: Superior Recovery on Door Opening

Reducing the frequency and duration of freezer door openings is vital for sustainable practices. The SU780XLE's excellent temperature recovery significantly contributes to energy savings in this regard. Independent testing has shown that even with nine 60-second door openings, the freezer consumes less than 10 kW/day (set at -70 °C). 

The Stirling engine's continuous, modulated cooling eliminates on/off cycling found in compressor-based models, ensuring more consistent temperatures within ±1 °C at steady state. Moreover, the freezer demonstrates a swift return to -80 °C after door opening, with a recovery time of just 35 minutes, as per ENERGY STAR® Final Test Method.

Benefit 4: Ultra-Cold Performance

The SU780XLE freezer consistently delivers ultra-cold temperatures, surpassing expectations. Independent testing has shown that at a setpoint of -80 °C, the warmest temperature recorded was -83.5 °C. Even at a setpoint of -70 °C, the Stirling freezer maintains an ultra-cold temperature of -71.5 °C or lower at all probe locations. 

These exceptional temperature performance features ensure the integrity and preservation of valuable samples.

Benefit 5: Extended Sample Protection

During power failures, the SU780XLE ULT freezer excels at safeguarding samples. With the ability to maintain a temperature below -50 °C for over 5 hours, organizations have valuable time to manage the situation and minimize potential sample loss. Using freezer racking in conjunction with the SU780XLE further extends samples to back-up units. Additionally, implementing color-coded freezer racking can further aid in identifying and rescuing critical samples in emergency situations.


The Stirling Ultracold SU780XLE ULT Freezer has earned its place in our Sustainable Solutions portfolio, as confirmed by the study conducted by Green Light Laboratories. This advanced freezer not only provides high-performance cooling but also excels in energy efficiency, space utilization, and high-capacity storage. 

With superior temperature recovery and the ability to maintain ultra-cold temperatures, the SU780XLE ensures the utmost preservation of samples. Laboratories can enhance their sustainability efforts, optimize efficiency, and rely on the SU780XLE ULT Freezer to protect their valuable samples for long durations.

By investing in the Stirling Ultracold SU780XLE ULT Freezer, laboratories can make significant strides towards sustainability, reduce energy consumption, maximize storage capacity, and maintain the integrity of their samples. With its exceptional features and performance, the SU780XLE is an ideal choice for laboratories seeking to enhance efficiency, sustainability, and sample preservation.

Contact SciQuip today to learn more about the Stirling Ultracold SU780XLE ULT Freezer and how it can revolutionize your laboratory's cold storage capabilities while aligning with your sustainability goals.