Abstract: Device for cool drying comprising a heat exchanger (2) whose primary part is the vaporizer (3) of a cooling circuit (4) which also includes a compressor (6) driven by a motor (5), a control device (16) for this motor (5) and measuring device (17) for the lowest air temperature (LAT), measuring device (18) for the ambient temperature (Tamb) and a flow meter (19), whereby this control device (16) can be at least switched in a first user mode in which the cooling circuit (4) is only activated when the gas flow exceeds a preset value and a second user mode in which the lowest air temperature (LAT) is maintained within a certain range by controlling the cooling circuit (4).