This standard shall be used to determine the structural strength@ dimensional stability@ durability@ and leakage characteristics of HVAC air ducts. 2.2 This standard does not address the following: a. Fittings b. Effects of aerosols@ solid particulates@ corrosive environments@ or combustibility c. Long-term effects of extended service d. Seismic qualifications e. Underground ducts f. Plenums and equipment casings g. Supports for ductwork and fittings PURPOSE This standard provides laboratory test procedures for the evaluation of HVAC air ducts.