© Copyright CalCERTS, Inc. 2019
Code Cycle: 2016 & 2019 Standards
Entirely new or complete replacement duct systems installed as part of an alteration shall be
- At least 75 percent new duct material.
- Up to 25 percent may consist of reused parts from the dwelling unit's existing duct system, including but not limited to registers, grilles, boots, air handler, coil, plenums, duct material; if the reused parts are accessible and can be sealed to prevent leakage.
- Entirely new or complete replacement duct systems shall also conform to the requirements of
Sections 150.0(m)12 and 150.0(m)13.
Duct systems that do not meet the definition of an Entirely New or Replacement Duct Systems shall be considered an existing or altered duct system.