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Ultra-Low Temperature Freezers (ULT Freezers) typically operate between -70 and -80oC, consuming between 16-22KWh of electricity per day, roughly twice the consumption of an average U.K household (9KWh/day). They are, therefore, some of the single most energy intensive pieces of general laboratory equipment. In the Clinical School these storage facilities are essential for storing or archiving biological samples.


Recently a group on behalf of the Clinical School led by Professor Nick Wareham carried out an options appraisal in order to both audit the current ULT storage facilities and to identify ways to improve its efficiency. It was discovered that departments within the Clinical School are directly responsible for 444 individual units across 161 rooms in 23 different locations. These 444 ULT freezers are responsible for approximately 3,800,000 kWh of energy per year, costing roughly £460,000. This is equivalent to around 3% of the total electricity consumption of the University’s operational estate.


Managing these storage facilities more effectively could help to significantly reduce both the University’s carbon emissions and electricity usage. The Clinical School as a result of this report are considering consolidation of their ULT storage, and replacing older units with newer more efficient ones. They are also encouraging better management of freezers across the school and for users, where possible, to raise the temperature of their freezers from -80oC to -70oC. This 10oC rise in temperature can reduce the energy consumption of an individual unit by 30%. They are also looking to introduce electronic inventory systems for all samples stored in ULT freezers.

This project has recently been submitted under the Green Impact: Excellence award scheme. 

Interested in managing your freezers and samples better? You can read our poster on 'Five ways to safeguard your samples & make your freezer last longer' or request a hard copy from our materials page.