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Applications for the 2024 Freezer Challenge will open in January 2024.

At Carolina, 40-60% of campus energy is used in our research labs and hospital buildings. Labs and hospital buildings are home to many ultra-low temperature (ULT) freezers (-80 degrees or colder), which  consume as much energy as a single family home.

This is where the Freezer Challenge comes in! UNC-Chapel Hill encourages labs to participate in My Green Lab’s Freezer Challenge, a free annual, international competition promoting best practices in laboratory cold storage.

In addition to making labs more sustainable, the actions outlined in the Freezer Challenge can help keep samples safer and avoid freezer failures in the long run. By avoiding freezer failures, labs can put their financial resources toward supporting trainee research and acquiring samples and reagents more quickly.

Video from My Green Lab’s 2022 Freezer Challenge.


The Freezer Challenge

My Green Lab’s Freezer Challenge scoresheets ask for responses in four categories. For more details on each of these four categories, see our checklist guide. 

Category 1: Good Management

  • Defrost Freezer Annually
  • Remove Dust from Intake and Coils. Backpack vacuums can be borrowed from UNC Housekeeping.
  • Remove Excess Frost/Ice, carefully with rubber tools
  • Clean Out Freezers
  • Maintain Inventory of Laboratory Samples
  • Utilize High Density Storage

Category 2: Temperature Tuning

  • Adjust Ultra-Low temperature (ULT) Set Points
  • Store Laboratory Samples at Appropriate Temperature Settings

Category 3: Retirements & Upgrades

  • Retirement Without Replacement
  • Retirement with Energy Efficient Replacement

Category 4: Sharing & Room Temperature Sample Storage

  • Sharing Freezer Space
  • Barcode Inventory
  • Room Temperature Sample Storage
  • Room Temperature Reagents and Kits
  • Recruiting Additional Labs to Participate


A research specialist within the Basta Lab opens a refrigeration unit housing biological samples in the Michael Hooker Research Center. The Basta Lab has won the UNC Freezer Challenge twice.
(Jon Gardiner/UNC-Chapel Hill)


Is my lab ready for the Freezer Challenge?

If your lab uses ultra-ultra low temperature freezers (above -96°C), ultra-low temperature freezers (-96 to – 40°C), lab freezers (-40 to -20°C), refrigerators, or cold rooms, you can participate in the challenge.

We also have a collection of blog posts, research papers, and posters that can be helpful in navigating the Freezer Challenge, if this is your lab’s first time entering.

How does participating in the challenge benefit my lab?

The benefits of participating are far reaching. Your lab can reduce energy consumption and environmental impact by applying good management practices and freeing up rack space. By taking an inventory of current samples and eliminating unneeded or unviable samples you can eliminate the need for some cold storage, thus reducing maintenance costs for your lab. You can also extend the life of cold storage units and improve stability and access to viable samples. Lastly, participating in the program gives you the chance to be recognized by your peers, both at your home institution and at an international level.

How do we win?

Labs can win at the international level through My Green Lab’s Freezer Challenge. Even if a lab does not win the My Green Lab Freezer Challenge, they do have a chance to win at the University-level. The UNC Freezer Challenge winner is the lab that scores the most points in the My Green Lab Freezer Challenge. The winner will take home a trophy and $5,000 for its next ultra-low freezer purchase!

How and when can I register my lab?

Registration for My Green Lab’s Freezer Challenge opens at the beginning of the calendar year and closes at the beginning of July. Labs must fill out an online form on the My Green Lab Website. From there, the lab will receive an email with a link to a scoresheet. Labs must fill out the scoresheet and submit before the deadline to be considered.

How do I earn points?

On the My Green Labs Freezer Challenge scoresheet, most actions count as 1 point. And if one action is carried out on multiple freezers, each freezer is generally a point. My Green Labs looks at the overall spread of data across all participating labs, for each question individually, and normalizes the points each lab earns so no single question on the Freezer Challenge scoresheet enables a lab to win. For most questions, the maximum normalized points a lab can earn on a question is 5.

Who do I contact if I have additional questions?

Please contact with any additional questions or comments.