Testing of a drop-in secondary loop refrigeration system for medium temperature supermarket applications.

Many of today's supermarket refrigeration systems are designed such that each refrigeration or freezer display case uses a separate direct expansion evaporator, all of which are connected in parallel to one or more primary compressors and condensers. These systems typically involve long lengths of refrigeration piping and large refrigerant charges. Secondary loop refrigeration provides an alternative solution to the traditional direct expansion. The cooled secondary fluid is pumped to the refrigeration or freezer display cases. The paper presents a comparison of test results between a baseline direct expansion system that is typically used in supermarket applications and a secondary loop system using two different thermofluids.