A method for controlling and adjusting the refrigeration capacities of a refrigeration system equipped with a double suction compressor, the refrigeration system including first and second compartments to be refrigerated and including first and second evaporators respectively positioned in the first and second compartments. The double suction compressor is controlled to alternate its compression capacity with high-frequency between first and second refrigerant suction lines respectively associated with the first and second evaporators such that the first and second compartments are simultaneously cooled. The compression capacity of the compressor is applied to the first and second suction lines based upon respective first and second duty cycles that together account for 100 percent of the compression capacity of the compressor. First and second temperature sensors are associated with the first and second compartments and provide temperature values that are used to select the first and second duty cycles.