A device for an air handling system in which the cooling beam has a pressure chamber (2), from which the volume flow of the supply air (L1) out to the room is regulated with a regulating strip (6) that is mounted on the surfaces (9) in the pressure chamber and where the flow of the supply air (L1), in the mixing chamber (4), provides an optimal flow pattern of the recirculating air (L2) from the room and where the combined flow of supply air (L1) and recirculating air (L2) acquire well defined flow profiles independent from the volume flow (L1).