Skip to main content
KBS_Icon_questionmark link-ico
;

How do you 'de-frost' an energy problem like cold storage?

Freezers play a crucial role in research at King’s, providing a controlled cold environment to store and safeguard valuable samples. As our research grows, there is increasing demand for cold storage, so it is important that we optimise our cold storage and biobanking infrastructure to meet demand and operate in the most efficient and sustainable way.

We know all too well the consequences of freezer failure and we were reminded in the news just last week of the tragic loss of embryos from errors in the freezing process. This serves as an important reminder to institutions like us of the importance of upgrading and maintaining the health of our cold storage infrastructure to safeguard and uphold sample integrity.

King’s currently has over 530 Ultra-Low Temperature (ULT) freezers, occupying nearly 2,000 m2 of highly serviced laboratory space. These units have a high carbon footprint, using up to 20 kWh of energy per day, the same amount of energy as two average UK households and further energy is needed to cool the space the freezers occupy because of the heat they produce. With this many ULT freezers, and 3-4 times more fridges and standard freezers in our labs (using 1-3 kWh of energy per day), there is a lot of untapped potential for tackling energy use in cold storage.

Thankfully, our newly formed Sustainability in Research team, Dr Marcelo Salierno and Caitlin Broadbent, have big ambitions for reducing our carbon footprint in research, aligning with King’s commitment to the Climate & Sustainability Action Plan. In collaboration with colleagues across King’s, the team aims to foster sustainable practices and pave the way for innovative alternatives that will drive impactful green-lab initiatives.

Caitlin and Marcelo

 

King’s has committed a significant investment to improve the sustainability of the cold storage and biobanking infrastructure and as part of this drive to optimise operations, King’s are delivering several initiatives, including:

  1. Freezer Exchange Scheme - offering departments the opportunity to replace their old inefficient ULT freezers, with new ultra-efficient, fully racked models on a 2 for 1 exchange basis. The aim is to encourage colleagues to improve freezer management and maintenance by clearing out samples that no longer need to be stored, consolidating and improving efficiency through best practice.
  2. Freezer Challenge - Open from January to July 2024, King’s is participating in the international Freezer Challenge, hosted by MyGreenLab in collaboration with I2SL, and designed to promote best practices in cold storage management and uniting labs worldwide in the quest for sustainable excellence.
  3. The Laboratory Efficiency Assessment Framework (LEAF) - provides a standard for Labs to work towards, to make their working practices more sustainable. This initiative supports a key goal within King’s Climate & Sustainability Action Plan for all our laboratories to achieve 100% participation in LEAF by 2025.   

To encourage participation in these initiatives, we’re running a pilot to better understand the practical requirements of implementing best practice and maintenance activities and recording the impact these maintenance behaviours have on energy consumption. Working alongside the School of Immunology and Microbial Sciences, we’re working to improve the efficiency of their ULT Freezers. The aim of the pilot is to learn and support staff by sharing knowledge, tips and tricks as well as building a community to support each other.

We know from a 2013 study into ULT freezer energy consumption that certain behaviours can increase the energy use of a ULT freezer, for example not cleaning a filter can increase energy use by 14%, and 25% if the condenser fins also have dust accumulation. Additionally, inappropriate spacing between freezers can increase energy use by 4%, so squeezing in as many ULT’s into a room as possible, increases energy use. Not only this but a packed freezer room generates a lot of heat, meaning additional air conditioning is needed to reduce the temperature, as higher ambient temperatures increase energy consumption of ULTs.

We also know from a case study by Green Light Laboratories in 2021, that whilst initial energy consumption needed to reach the set point temperature is greater in racked freezers, the racking holds the temperature better, meaning it operates more efficiently when the door is open and during breakdowns. Opening a freezer door for extended periods of time increases the internal temperature, therefore warming up all samples. This isn’t great for sample integrity and can waste a lot of time.  

We understand that tackling these problems can be difficult and overwhelming, especially when you have samples that are tricky to identify. That’s why we’re running a pilot to better understand freezer requirements, from utensils to time, to organising and improving cold storage practices.

How we are conducting the pilot  

  1. Identifying five freezers to improve
  2. Monitoring the energy usage
  3. Organising, defrosting, cleaning the freezer
  4. Monitoring energy usage again
  5. Assessing the energy use before and after 
  6. Producing a “how to guide” on organising ULT freezers

Why do we need to organise and maintain our freezers better?  There are many benefits of defrosting and organising your freezer. These include;   

  • reducing energy consumption  
  • reducing door opening times - samples stay colder longer  
  • increasing temperature uniformity - racking retains temperature  
  • reducing time spent looking for samples  
  • reducing risk of breakdown  
  • understanding which freezers are most suitable for replacement.  

We’ve teamed up with T-Scan, an environmental monitoring solutions company, to monitor the energy usage before and after each change to see what impact they have on the energy use of these freezers. Where the energy use is not sufficiently reduced, we’ll be looking to trade in freezers as part of King’s 2 for 1 Freezer Exchange Scheme. We can then remove our old inefficient freezers, reduce our cold storage footprint and commission new energy efficient freezers with appropriate racking. 

The end goal of the pilot is to reduce energy consumption, and ultimately reduce the carbon impact of freezers here at King’s, but there are many benefits to gain from tackling the health of our freezers, including making samples easier to find, and saving time and money by reducing the chance of repeating or rebuying the same sample. Installing an energy meter monitor also has the added benefit of alerting users of a wattage drop in the event of a power cut or breakdown.  

The pilot is also perfectly time to support the 2024 Freezer Challenge. Every King's lab has been invited to take part, and our sustainability team is gearing up to equip teams with resources and training, and recommendations for enhanced sample management and freezer maintenance.

The challenge goes hand-in-hand with the Freezer Exchange Scheme, enabling teams with several cold storage units to maximise the benefit and upgrade their infrastructure as an added bonus.

These initiatives are all designed to work together and side-by-side, with aims to improve the efficiency and sustainability of our cold storage and biobanking infrastructure so that we can continue to deliver world class research at King's. Our target is to reduce King’s net annual energy consumption by 1M kilowatt hours, the same amount of energy needed to power over 300 average UK homes per year. We look forward to reporting on the results of these schemes in the future, so please do keep your eyes peeled for updates via this blog.  

We are encouraging those involved in the management of cold storage at King’s to follow our progress in this pilot and share their own efforts organising and improving their cold storage.

King’s Staff and Students can visit the Sustainable Research SharePoint for more information on our initiatives, and external visitors can follow our progress here. Contact us at sustainablelabs@kcl.ac.uk.   

Ripple Effects

Ripple Effects is the blog from King's Climate & Sustainability, showcasing perspectives from across the King's community.

Latest news