The Caracas of the plenum will be made of extruded aluminum sections in such a manner that the air is passed only through the filters only. Plenum unit for laminar flow diffuser will be made of thick aluminum sheet. The complete unit will have factory prepared fine sealing system. The plenum will be supplied at site duly sealed in factory made packing. The Laminar flow system will have anodized aluminum perforated diffuser grill. The laminar flow system will have such design that it provides cleanliness of class