The Chemistry Building Operations team continues to push the margin of equipment energy efficiency with their recent purchase of a new type of -80 freezer that consumes less than half of the electricity used by traditional cascade models.

The new unit, a Stirling SU780U produced by Global Cooling Inc., utilizes a single free piston Stirling engine as opposed to traditional dual-compressor systems. The many advantages of the Stirling freezer include increased reliability, lower maintenance costs, faster pull-down time from ambient to -80°C, faster door opening temperature recovery, premium temperature stability and uniformity, and more. Stirling engines have been used in a variety of applications since the 1800’s, and have entered the -80°C freezer market in recent years due to increased demand for energy efficiency. 

The new freezer at Chemistry was purchased as part of a pilot program to assess the effectiveness of providing incentives to encourage energy-efficient freezer choices when new units are needed. The Faculty of Arts and Sciences (FAS) Office for Physical Resources and Planning (OPRP) provided an incentive to cover the premium cost of the unit, making it cost competitive with other models on the market. This pilot program is the first of its kind for FAS, and if it proves successful, will likely be expanded school-wide to encourage the purchase of energy efficient freezers.

This program is part of a larger initiative at FAS to effectively manage its portfolio of -80 freezers, which are among the most energy intensive types of lab equipment on campus. With almost 200 units at FAS, mitigating the energy consumption of these freezers is an important step in meeting campus-wide energy reductions goals.

To learn more email energy@fas.harvard.edu.