Guidelines ultra-freezers

Did you know that ultra-freezers use as much energy every day as two households a year?

The presence of many individual freezers requires a lot of energy. A -80°C freezer consumes about 6,500 kWh annually (comparable to twice the energy consumption of an average Flemish family). If we want to drastically reduce energy consumption, to which UGent has committed in its energy policy plan, we must not only invest in sustainable and fossil-free buildings, but also focus on the rational use of energy-guzzling appliances, including these ultra-freezers. Therefore, the following guidelines apply:

  • Look into the possibility of purchasing or using a freezer together with several research groups. This not only saves costs in consumption, but also in purchase and maintenance.
  • We recommend an ultrafreezer with a  stirlingmotor (e.g. Stirling Ultracold Model SU780XLE).  Such an ultrafreezer is more expensive to buy compared to a conventional model, but uses up to 25%-30% less electricity. The overall cost of a stirling ultrafreezer is much lower than that of a conventional model. As an added bonus, these ultrafreezers use a refrigerant with a low GWP (global-warming potential), where classic ultrafreezers require fluorinated refrigerant gases that have a high GWP.
  • Let the operating temperature depend on the type of material. For example, many materials can be stored at -70°C! A freezer at -70°C has 25-35% less energy consumption than a freezer at -80°C. The University of Boulder, Colorado compiled a lijst of 119 biological samples that can be stored at -70°C or even warmer. A backup freezer can be kept at -50°C. The Department of Plant Biotechnology and Bioinformatics (WE09) has set all ultra-freezers at -70°C. For more information, see also the sheet '-70 is the new -80

  • Defrost every ultra-freezer annually. The ice formed takes up space and increases energy consumption. This saves about 20% in energy consumption.

  • When defrosting each year, take the opportunity to organise everything and get rid of unknown or unnecessary products; this will create space again.

  • For long-term storage, use the central UGent biobank.

  • To monitor electricity consumption, UGent decided to install counters on all individual ultrafreezers to make costs transparent and to pass them on in case of unnecessary or excessive consumption.

Central biobanks

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