Cold storage in labs- not a hot topic, but extremely important

Adriana Wolf Perez, PhD
2 min readMar 23, 2024

Cold storage is one of the biggest energy consumers in labs. In fact, ultra-low temperature freezers can use as much energy as an average household every day.

There are many factors that further significantly increase the energy usage of freezers and fridges:

· Lack of maintenance: filters are not regularly cleaned and are full of dust, fridges and freezers are not defrosted

· Many freezers are colder than they need to be. -20°C freezers are often actually programmed to -24–28°C (and in that case, the freezer consumes 20–50% (!) more energy)

· We often store a lot of “junk” and fill up fridges and freezer. It also takes us more time to find the samples we need when there is chaos, leaving the freezer or fridge door open longer.

· Bad lab layout: Cold storage generates a lot of heat (especially when freezers are positioned too close) making the air conditioning work harder.

There are 4 things that you can do to save energy related to cold storage:

1. Perform maintenance. Clean filters and remove ice build-ups. To make sure this happens, assign people in the lab to take turns.

2. Perform a biannual freezer declutter day: organization is key!

3. Exit protocols: before people leave the lab for a new position, go through freezers and fridges to find out which samples can be discarded

4. Check the real temperature of your freezer and change it to the desired temperature.

5. Try to rearrange your cold units so that the heat can dissipate more easily

Here is some more food for thought:

One -80C freezer can be roughly equivalent to the energy usage of ten -20C freezers! They use a lot of energy. However, there is a lot of evidence showing that many samples are stable and safe at -70C instead of -80C. It may not be advisable for all samples, but you will be surprised that many samples can be stored long-term at -70C. This adjustment can save your lab 20–40% of energy, depending on the freezer model. However, it is advisable to make sure someone else has performed long-term sample testing at -70C or perform this in a small scale yourself. You don’t want to destroy your samples!

If you want more information about advice on more sustainable cold storage practices, visit Freezer Challenge.

Listen to our podcast episode for more information here: