Patent ID: 7104083

Claim:
A refrigeration system of the type having a compression stage, a condensation stage, an expansion stage and an evaporation stage, comprising: a first evaporator group in the evaporation stage, the first evaporator group having at least two evaporators, the at least two evaporators of the first evaporator group being in separated refrigerated enclosures; a first valve positioned on a line common to the at least two evaporators of the first evaporator group, the first valve being closeable to block a supply of refrigerant to the at least two evaporators of the first evaporator group simultaneously for a subsequent air defrost of the at least two evaporators of the first evaporator group; a second evaporator group in the evaporation stage, the second evaporator group having at least one evaporator, one evaporator of the first evaporator group and one evaporator of the second evaporator group being in a common refrigerated enclosure; and a second valve positioned on a line common to any evaporator of the second evaporator group, the second valve being closeable to block a supply of refrigerant to the at least one evaporator of the second evaporator group for a subsequent air defrost of the at least one evaporator of the second evaporator group; whereby the first evaporator group and the second evaporator group are switchable to an air defrost mode independently from one another.