Abstract: A chute formed from a number of rigid panels supported by a support structure to define a duct for distributing and delivering cold air from a refrigeration unit located at one end of a cargo space such as a truck or railcar, toward substantially the other end, for treating cargos which require refrigeration such as perishable vegetables; fruits, plants or any food or similar products. In addition, the panels are formed to cleanse and to filter a portion of the distributed air by the incorporation of air treating or filtration agents within the panels.