Present supermarket refrigeration systems require very large refrigerant charges for their operation and can consume as much 1 to 1.5 million kWh annually. Several new approaches, such as distributed, secondary loop, and advanced self-contained refrigeration systems, are available that utilize significantly less refrigerant and with correspondingly lower refrigerant losses through leakage. New condenser controls have also been developed for multiplex refrigeration systems that allow operation with a refrigerant charge close to the critical level and also allow operation at very low head pressures. Through proper design and implementation, these advanced systems can reduce annual energy consumption by as much as 11.9%. Integration of refrigeration and store HVAC operation is also possible through water-source heat pumps. By incorporating the heat pumps in the heat rejection loop for the refrigeration, the reject heat can be utilized for store space heating without increasing the condensing temperature of the refrigeration. This integrated method was shown to reduce combined operating costs for refrigeration and HVAC by 12.6%.

Units: I-P