© Copyright CalCERTS, Inc. 2019
Code Cycle: 2016 & 2019 Standards
Altered Space-Conditioning System - Duct Sealing:
In all Climate Zones, when a space-conditioning system serving a single family or multifamily dwelling is altered by the installation or replacement of space-conditioning system equipment, including:
- Replacement of the air handler,
- Outdoor condensing unit of a split system air conditioner or heat pump, or
- Cooling or heating coil;
The duct system that is connected to the altered space-conditioning system equipment shall be sealed, as confirmed through field verification and diagnostic testing in accordance with the applicable procedures for duct sealing of altered existing duct systems as specified in Reference Residential Appendix RA3.1 and the leakage compliance criteria specified in subsection i, ii, or iii below. Additionally, when altered ducts, air handling units, cooling or heating coils, or plenums are located in garage spaces, the system shall comply with Section 150.2(b)1Diic regardless of the length of any new or replacement space conditioning ducts installed in the garage space.
i. The measured duct leakage shall be equal to or less than 15 percent of system air handler airflow
as determined utilizing the procedures in Reference Residential Appendix Section RA220.127.116.11.1; or
ii. The measured duct leakage to outside shall be equal to or less than 10 percent of system air handler
airflow as determined utilizing the procedures in Reference Residential Appendix Section RA18.104.22.168.4; or
iii. If it is not possible to meet the duct sealing requirements of either Section 150.2(b)1Ei or Section 150.2(b)1Eii, then, all accessible leaks shall be sealed and verified through a visual inspection and
a smoke test by a certified HERS Rater utilizing the methods specified in Reference Residential
EXCEPTION 1 to Section 150.2(b)1E: Duct Sealing. Duct systems that are documented to have been
previously sealed as confirmed through field verification and diagnostic testing in accordance with
procedures in the Reference Residential Appendix RA3.1.
EXCEPTION 2 to Section 150.2(b)1E: Duct Sealing. Duct systems with less than 40 linear feet as
determined by visual inspection.
EXCEPTION 3 to Section 150.2(b)1E: Duct Sealing. Existing duct systems constructed, insulated or
sealed with asbestos.