This simple to use but effective application is provided by the Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA). This tool allows engineers, architects, designers, and contractors to easily and accurately estimate the leakage of air from ductwork. It also allows a quick and easy way to determine the pass/fail mark for properly specified Duct Air Leakage Tests (DALT).

Users can combine multiple sections of ductwork that vary by size and shape to calculate a total allowable leakage. The application uses the method outlined in SMACNA’s HVAC Air Duct Leakage Manual, and provides suggested leakage classes from SMACNA’s latest edition of the manual. The method used is compliant with ASHRAE 90.1, IECC, IGCC Version 2, IMC and the UMC.