Abstract: The invention relates to a system that is functionally associated with a refrigeration unit (1), said system comprising a primary tank (6) for the inflow of the water to be treated, and an inner tank (7) for cooling and mixing the water. Said tank (7) contains an exchanger (13) through which the liquid gas from the refrigeration unit (1) is passed, at the same time as the water entering the primary tank (6) accesses the cooling and mixing tank (7) from the primary tank, said cooling and mixing tank comprising water suction tubes (23) that converge in a three-way valve (25) connected to a water recirculation pump (15) via which the water is driven inside the exchanger (13). The treated water leaves via an outflow line (27).