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Award for Efficient Cold Storage Management International Freezer Challenge: Who Saves the Most?

Author / Editor: Kerstin Hermuth-Kleinschmidt* / Dipl.-Chem. Marc Platthaus

Freezers are among the biggest energy consumers in a lab, and as a result they can cost a lab a lot of money. The International Freezer Challenge promotes best practices in cold storage management and awards the labs who have done the most to save energy and improve their sample storage.

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1 A lot of energy is needed for storing and cooling samples. This creates enormous savings potential.
1 A lot of energy is needed for storing and cooling samples. This creates enormous savings potential.
(Source: ©paul_burns -

Resource consumption in labs is high, and that costs a lot of money. Freezers and refrigerators are major power consumers. The daily power consumption of a freezer, particularly if it is an older model, can be as high as 30 kWh, more than for a single-family home [1]. Labs, especially molecular biology labs, store large numbers of samples at low temperatures. This can account for up to 20% of energy consumption in molecular biology labs. However by taking some very simple steps, users can help save energy. With this in mind, two American non-profits launched the Freezer Challenges. The purpose of the challenge is to share information about best practices and encourage people to implement these practices in their own lab. In 2017, the Freezer Challenge was established nationwide inviting all North American labs to participate. It is organized by My Green Lab [2] and I2SL – International Institute for Sustainable Laboratories [3]. Last year, more than 200 labs participated, saving a total of 2.7 million kWh which is equivalent to 1,900 mt of carbon dioxide. Following disposal of more than 200,000 surplus samples, old inefficient freezers were permanently retired [4].

Additional Information
The Freezer Challenge

Every participating lab reports on the action it has taken during the competition period and is awarded points for each item. Important: If the lab has already taken action, for example turning the freezer temperature down to -70 °C, this should be reported as well and it will be included. Once the lab has entered the information about the action taken, the completed questionnaires are sent back and evaluated. The evaluation is based on the point total for the action taken.

  • When: from now until May 1, 2018.
  • Prizes: Various prizes will be awarded to labs in the academic, government and private sectors and companies which take part in the international competition.

The winners will be announced in the journal Nature, and they are invited to attend the I2SL conference. Egnaton will also present an award to the three best European labs and invites them to attend the 2018 Egnaton conference.

In 2017/2018, the Freezer Challenge has been expanded to a worldwide competition, having started in October 2017 and continuing until May 1, 2018. Institutes and labs at public institutions, universities and companies will take action to reduce their environmental impact and have the chance to win prizes. At the European level, Egnaton — the European association for sustainable laboratory technologies — is supporting the competition [5]. In addition to the international prizes, the three best labs in Europe will receive the European Egnaton Award.

Advantages of sample and freezer management

Good freezer maintenance can reduce energy consumption by 12% and 25%, and it has economic as well as ecological benefits.The average savings potential of a maintained freezer is estimated to be 280 $ per year [1]. What does good freezer management look like? First of all, regular defrosting helps reduce energy consumption and extends the useful life of freezers and refrigerators. Depending on thickness, a layer of ice can increase energy consumption by 10% to 50% in the worst case (a layer of 5 mm already increases the energy consumption by 30%). When ice builds up, the compressor has to work harder to maintain a constant temperature, and that can reduce the life of the compressor. In the worst case scenario, ice can damage the door seals which in turn impairs cooling performance and puts the samples stored inside at risk [1]. Filters should be checked regularly, ideally once a month, to make sure they are not clogged with dust, and they should be cleaned or replaced as necessary. A clogged filter prevents good airflow to and from the condenser and inhibits the extraction of warm air from the refrigerator interior. In addition, contamination from the filter can be deposited on the condenser. The layer of dust prevents efficient heat extraction. The condenser has to work harder, uses more energy and wears out faster [1]. Other recommendations include taking an inventory of the samples and introducing good sample management. If the stock is always up to date, no space is wasted keeping samples that are no longer needed. Compact storage in the smallest possible tubes, microtiter plates and deep-well plates (high-density storage) also makes optimal use of the available space. Keeping an inventory using an Excel spreadsheet or barcodes makes it easy to locate the samples. This saves time and one takes care of the freezer. Since, for every minute that the freezer door is open, the compressor must work for ten minutes to restore the original temperature.