Patent ID: 8020389

Claim:
Climatic test chamber, in which during a sequence of specified test cycles at least one test cavity is cooled down to and maintained at a minimum set temperature by a refrigerating unit including at least a refrigerating circuit where a refrigerant medium flows therethrough, comprising: a compressor, with a delivery pipe and a suction pipe, driven by an electric motor, whose rotating speed is adjustable between a maximum value and a minimum value, a condenser, an evaporator having an inlet and an outlet, a throttling device located at the end of a main pipe, between the condenser and the inlet of the evaporator, a tank which is filled with a cold storage medium and through which there are caused to pass: a secondary pipe extending between a first and a second fitting along said main pipe, upstream of said throttling device, a recovery pipe extending between a third fitting downstream of said second fitting along said main pipe and a fourth fitting along said suction pipe; means for selectively controlling the flow of the refrigerant medium through the main pipe, the secondary pipe, and the recovery pipe so as: to have cold storage medium cooled by the refrigerant medium flowing through said secondary pipe during the steps of the test cycles in which said test cavity is maintained at the minimum set temperature, said steps being carried out with the drive motor of the compressor operating at the minimum rotating speed thereof, and to recover the cold accumulated by the cold storage medium, by subcooling the refrigerant medium flowing through said secondary pipe during the cooling-down steps of the test cycles, said steps being carried out with the drive motor of the compressor operating at the maximum rotating speed thereof.