In molecular biology, biotechnology, and clinical diagnostics, ultra-low temperature (ULT) freezers play a critical role in safeguarding the integrity of biological samples. But as laboratories scale their research and storage demands, the sustainability and operational impact of ULT units has come under increasing scientific scrutiny.

This article explores the recent research that’s reshaping how experts view ultra-low temperature storage — with a special focus on energy efficiency, sample stability, and evolving best practices in laboratory environments.

ULT Freezers: Quiet Energy Guzzlers in Research Labs

Although essential, ULT freezers are some of the most energy-intensive devices in the modern lab. A 2016 Nature feature titled "The Quiet Energy Hog of the Lab" estimated that a standard –80 °C freezer consumes as much electricity as a typical U.S. household — approximately 15 to 20 kWh per day.

Multiply that by the number of freezers in a medium-sized institution or biobank, and the operational cost and carbon impact become significant. According to My Green Lab’s Center for Sustainable Labs, ULT freezers can account for 30% to 50% of a lab’s total electricity use, depending on infrastructure and usage patterns.

Scientific Institutions Respond: From Guidelines to Temperature Setpoints

In response, major research institutions have taken the lead. The NIH, European Molecular Biology Laboratory (EMBL), and University of California system have implemented programs encouraging:

• The purchase of Energy Star–rated ULT freezers
• Raising storage temperatures from –80 °C to –70 °C, which can reduce energy consumption by 30–40% without compromising most sample types
• Implementing maintenance and defrost schedules to improve freezer performance
• Auditing freezer fleets to remove underutilized units

A 2021 Cell Press article, “Decarbonizing the Laboratory Cold Chain,” emphasized that strategic changes to freezer management can have a measurable effect on research institutions’ emissions — often without requiring massive overhauls.

The Hidden Variable: Thermal Stability and Sample Quality

While energy efficiency garners attention, equally critical is the thermal performance of ULT storage. Several studies have shown that minor fluctuations in internal freezer temperature — especially during door openings or power interruptions — can degrade sensitive biomolecules such as RNA, enzymes, and certain cryopreserved cell lines.

A 2020 paper published in the Journal of Biomolecular Techniques found that repeated temperature deviations greater than ±5 °C significantly increased degradation rates in enzyme activity over a six-month storage period. Similarly, long-term storage of DNA at unstable temperatures was linked to lower yield and increased shearing during extraction.

Thus, experts now call for greater attention to uniformity and recovery time, especially in biobanking and regulated environments where sample integrity is paramount.

What Researchers Are Doing Now

Across the biotech, forensic, and diagnostics fields, scientists are adopting a range of strategies to adapt:

• Reducing door-open events with better inventory planning
• Using sample temperature loggers to monitor actual exposure conditions
• Prioritizing ULT units with fast temperature recovery and minimal fluctuation
• Advocating for freezer sharing programs to reduce fleet size without compromising access

Lab sustainability officers are also playing a growing role, advising procurement teams to balance performance with lifecycle cost, noise levels, and ecological footprint.

A Shift in Mindset

The conversation around ULT freezers is evolving from “cold and reliable” to “cold, stable, and sustainable.” The shift is driven by a convergence of scientific insight, energy data, and institutional responsibility.

As Dr. Liza Boucher, senior researcher at the Centre for Molecular Storage Systems, puts it:

“The real challenge isn’t just storing samples at –80 °C — it’s doing so without compromising sample quality, budgets, or the planet.”

 

Whether your priority is sample integrity, energy efficiency, or compliance, modern ULT systems exist to support these goals. Discover how ProLab Supply supports this shift.

 

 

Sources

• Nature (2016). The quiet energy hog of the lab.
• My Green Lab (2023). Center for Sustainable Labs Reports.
• Cell Press (2021). Decarbonizing the Laboratory Cold Chain.
• Journal of Biomolecular Techniques (2020). Thermal Stability of Enzymatic Reagents in Ultra-Low Freezers.
• EMBL Sustainability Guidelines.