The paper details the replacement of an existing HFC based refrigeration plant with a low charge NH3 based central refrigeration plant. On the basis of electricity consumption records, the paper will detail the actual energy performance of the new DX, NH3 system in comparison with the former HFC system.

The refrigeration system has low and medium temperature design cooling capacities of 45 and 49 kW respectively servicing a refrigerated volume of ~5,250 m³. This categorizes the warehouse as a small to medium size facility.

The ambient conditions in Tropical Queensland, Australia where the site is located cause energy efficiency challenges for natural refrigerant based HFC alternatives such as transcritical CO2.

The paper will discuss the technical and economic viability of NH3 DX based solutions for the small to medium capacity range such as this. In addition, the paper will provide technical details and images of the former HFC plant as well as the replacement NH3 installation.