Background: The Mayo Clinic Biorepository Program Biospecimens Accessioning and Processing (BAP) Core Laboratory has a variety of storage options with a capacity of over 30 million samples, including 4 automated -80°C freezers, 150+ upright -80°C freezers, and 12+ liquid nitrogen freezers. As our biorepository continues to grow, energy efficient options are being considered to replace the aging -80°C freezers, but must maintain adequate performance characteristics and storage capacity. The purpose of this study is to compare the performance characteristics and cost effectiveness of the 3 newest energy efficient upright -80°C freezer models.
Methods: The Thermo Fisher TsX600, Panasonic VIP ECO, and Stirling Ultracold freezers were installed in our facility for comparison. The method from the study performed in 2014 was recreated for this study. Power usage, power surges, capacity, temperature fluctuation, temperature gradient, recovery time, and warm-up profile were measured. Idle to heavy usage conditions were simulated over a 3 week period. A financial analysis using our results with local power costs was completed to determine operating cost of each freezer over time.
Results: The Mayo Clinic BAP Core Laboratory determined how the new energy efficient -80°C freezer models compared to one another and whether or not they outperformed standard upright and liquid nitrogen freezers from our study performed in 2014. We determined whether, at a reduced energy cost, these new models are the best -80°C storage option for biorepositories looking to save on operating costs and reduce their energy consumption.
Conclusion: The new energy efficient models have features that improve their ease of use and on-board monitoring over previous standard upright models. Comparison of these storage units has helped our program evaluate the most efficient and cost-effective storage units for our continually expanding biorepository.