Air Tightness of Ventilation Ductwork Equipped with Joints

The average air tightness of the ventilation ductwork in France is rather poor, corresponding toa 3A class. This is mainly due to air leakage in the fittings. Because of difficulties encounteredduring the implementation as lack of space, access problems or short time to proceed theinstallation, these fittings are not sealed enough, with mastic or adhesive tape.In order to limit this risk of leakage and to limit sealing operations on site, manufacturerspropose components equipped with joints. Some years ago, CETIAT has tested in itslaboratories different kind of such components. The results obtained demonstrated the ability ofthese elements to achieve a good air tightness (class C). In order to determine in realconditions on site whether these results could be maintained, CETIAT has performed sometests on different kind of ductworks in an office building, in a technical school and in amultifamily building.