Modular low charge hydrocarbon refrigeration system and method of operation

To meet commercial refrigeration demands while also complying with hydrocarbon charge regulations, a merchandiser will typically employ a plurality of refrigeration circuits that operate in parallel. A plurality of parallel refrigeration circuits have the disadvantages that additional components are necessary to operate each of the separate refrigeration circuits, and that parallel refrigeration circuits do not maximize cooling load so a greater amount of hydrocarbon refrigerant is necessary to operate the refrigeration circuits than should be required. Both of these disadvantages increase costs. To decrease costs, the present system does not include parallel refrigeration circuits, but is instead configured in a different design to meet commercial refrigeration demands while decreasing costs. The refrigeration system includes: a refrigeration loop including a compressor, a first heat exchanger, and an expansion assembly, and a second heat exchanger interconnected by a first piping loop, the first piping loop circulating a hydrocarbon refrigerant; and a cooling loop circulating a cooling fluid in direct heat exchange relationship with the hydrocarbon refrigerant within the second heat exchanger, the cooling loop including a pump interconnected with the second heat exchanger and a third heat exchanger by a second piping loop, wherein the first heat exchanger is in heat exchange relationship with an airflow passing through the first heat exchanger, and wherein the airflow is in communication with a space adapted to support product to be cooled, and wherein the third heat exchanger rejects heat to an ambient environment.