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To develop an effective Ultra-Low Temperature Freezer (ULT) management program at Auburn University, we must first understand the landscape of campus freezers.  Questions we’re hoping to answer include:

  • How many freezers do we have?
  • Where are they located?
  • Who operates them?
  • How old are they?
  • How are they maintained?

To gather this information, the Office of Sustainability staff will visit campus buildings to assess equipment.  We would love for researchers and lab technicians to assist with this effort by participating in brief interviews (<15 minutes) on their freezer equipment!

We’ll start with buildings we know contain many ULTs and then move on to other areas afterward.  If you would like to participate in an interview, please select the appropriate sign up form based on your building.  If you’re building isn’t listed or the days/times given for your building don’t work with your schedule, please select the any building sign-up.  If those days/times also don’t work, please email to arrange a time for us to visit.

We appreciate your help and encourage you to share information about this effort with your colleagues!

Best Practices for Ultra-Low Temperature Freezers

Ultra-Low Temperature Freezers (ULTs) are essential equipment for researchers and scientists. These ULTs require a significant amount of energy to maintain low temperatures. Improper care of ULTs can lead to elevated energy costs, damage to samples, and leakage of greenhouse gases. Below is a guide of best practices in order to lighten your ULT’s energy burden and maximize its life.


  • Filters should be inspected monthly. 
  • Clean the filter by vacuuming the filter door to remove dust. Wash the filter with soap and water. Let it air dry before reinserting.


  • Inspect the door gasket for tears and deformities regularly.
  • Wipe frost from around the gasket and between the folds.


ULTs should be defrosted regularly.

  1. Remove samples.
  2. Shut down unit.
  3. Prop open doors & melt all ice.
  4. Completely wipe & dry unit. 
  5. Reach set point temperature & replace samples.


  • Keep samples organized.
  • Use an inventory management system.
  • Clean samples out regularly.


  • Pre-cool samples in a -20ºC freezer before placing them into a ULT.
  • Don’t overfill.

Air Flow 

  • Freezers should be tightly packed together  
  • Keep 8” of clear space above the freezer. 
  • Keep 5” of space behind.  


  • Place freezers near the room’s return vent.  
  • Rooms at cooler temperatures (<72ºF) can ease the energy load on the ULT. 
  • Don’t place ULTs in hallways.


  • Consider increasing the set point to -70ºC.
  • Research on the benefits of raising the temperature:“-70 is the New -80”


  • Regularly wipe frost off of surfaces with a soft cloth.
  • A brush or scraper can be used to clean harder to reach places or more dense frost.
  • Be careful to not puncture the door gasket.


A presentation from ThermoFisher on ULT best practices which also includes a 12-point maintenance checklist.

Eppendorf has an excellent 1-page maintenance guide.

The National Institutes of Health did a case study on the factors that affect the performance, energy consumption, and carbon footprint of ULTs.

Store Smart’s: Everything You Wanted to Know about Running an Ultra Low Temperature Freezer Efficiently but Were Afraid to Ask

ThermoFisher created a guide to maintenance and upgrades.

My Green Lab has an excellent general resource page. You can find resources on preventative maintenance, increasing set-point temperature, and energy efficiency.

My Green Labs has created a comprehensive list of resources that can assist you in evaluating sustainability metrics such as tax rebates, energy efficiency, carbon footprint, and more when purchasing a new ULT.