“…In this work the domain has been extended in order to cover a wider range of some parameters, first of all the subcooling degree, and to include new variables such as the subcooler activation temperature and the subcooler set point temperature. The computations have been performed by means of a comprehensive model built in the Trnsys environment [19], which includes the transcritical CO2 booster refrigeration unit, as well as the display cabinets and cold rooms [20,21], and a R-1234yf DMS unit. The model has been calibrated and validated against the field data gathered during a whole year from the monitoring of an actual refrigerating system in operation in a small sized supermarket located in Northern Italy as described by Cortella et al [22] and D'Agaro et al [23].…”