The invention relates to a cooling circuit system, comprising a plurality of juxtaposed racks; a double bottom consisting of double bottom elements mounted on a base bottom on which double bottom the racks are mounted; electric or electronic components to be cooled, which components are accommodated in the racks; and a cooling system, the components of which are accommodated in the double bottom, wherein the cooling system comprises fans that are connected in parallel and that blow cooled air from the double bottom towards the juxtaposed racks. The invention relates also to a method of controlling a cooling circuit system of that type.