Supermarket, booster, waste heat, Energy efficiency
Carbon dioxide (CO2) being a low Global Warming Potential (GWP) refrigerant is becoming a popular choice as an efficient refrigerant in supermarket refrigeration systems, not only in moderate climates such as Northern Europe but also in the United States. Due to its low critical temperature (31.06°C), CO2 systems also offer potential for waste heat utilization. This paper, therefore, aims to uncover this potential for the US supermarket refrigeration industry through simulation. In this process, the whole building energy modeling tool, EnergyPlus, has been used to investigate the energy consumption of a supermarket utilizing packaged rooftop air conditioning units and a transcritical CO2 booster refrigeration system. The energy impact of humidity control within the supermarket, both on the HVAC and the refrigeration systems, is investigated. Also, a desiccant system incorporating waste heat for desiccant regeneration has been analyzed. Finally, the performance of the transcritical CO2 booster refrigeration system is compared with the baseline R404A multiplex direct expansion system using bin analysis in sixteen cities from eight climate zones of the United States.