At the Dunn School, University of Oxford, our dedication to energy efficiency and minimizing environmental impact shines with the 'Cooler at -70' Ultra-Low Temperature (ULT) Freezer Initiative.

ULT freezers, pivotal for bio-sample storage, rank high in energy consumption in research hubs. Historically set at -80°C, research indicates effective sample preservation at -70°C. Aligning with this, our standard ULT freezer setting is now -70°C, realizing energy savings up to 30%.

Initially, Wayne Swan and Marcus Bottomley conducted tests using energy monitor on old emergency freezers and found a 30% decrease in energy consumption at -70°C. Thanks to Wayne Swan's initiative, and in collaboration with the Dunn School and the University of Oxford's sustainability funds, new energy-efficient freezers were installed in a few initial labs, including the Raff Lab. These freezers were already saving 30% more energy at -80°C. The Raff Lab, led by Saroj Saurya and assisted by Wayne Swan and Martin Smith, tested these new freezers at -70°C and observed an additional 30% energy savings. This was encouraging, and then Wayne Swan was able to persuade several more labs to increase their freezer settings from -80°C to -70°C. Geoffrey Smith, who had moved his lab from Cambridge where ULTs were already operating at -70°C, then joined forces with Wayne Swan and Saroj Saurya to encourage all the group leaders to make this change. While exemptions exist for specific -80°C needs, the emphasis lies on the manifold benefits: carbon footprint reduction, freezer longevity, and cost savings, culminating in an annual departmental saving of approximately $300,000!

With 'Cooler at -70' as a beacon, the Dunn School continually imbibes sustainability in research. Indeed, for us, -70 is the evolved -80!