18-28-603.9 Supports.
   Ducts shall be supported with approved hangers at intervals not exceeding 10 feet (3048 mm) or as specified in the SMACNA HVAC Duct Construction Standards – Metal and Flexible or by other approved duct support systems designed in accordance with the Chicago Building Code. Flexible and other factory-made ducts shall be supported at least every 5 feet (1524 mm).
(Amend Coun. J. 9-14-21, p. 35949, Art. VI, § 6)