MINHERS Interim Addendum 47i

On April 5th, 2020, a new RESNET Standard Addendum called Addendum 47i went into effect. If you’re like us, you may have been a bit confused at first. There is a lot of language around duct testing exemptions between Addendum 39, ANSI 301-2019, and this new Addendum 47i. Hopefully this will help clarify things. The only thing Addendum 47i changes is that duct leakage testing can be waived for homes that use building cavities as ducts, as long as the home is permitted prior to Jan 1, 2021. Here’s a summary of what you need to know: For homes permitted before January 1, 2021: All duct testing (both leakage to outside and total duct leakage) can be waived when the following condition is met:

• At a pre-drywall stage of construction, 100% of the ductwork and air handler shall be visible and visually verified to be contained inside the Conditioned Space Volume. At a final stage of construction, ductwork that is visible and the air handler shall again be verified to be contained in the Conditioned Space Volume.

For homes permitted on or after January 1, 2021: All duct testing (both leakage to outside and total duct leakage) can be waived when the following conditions is met:

• At a pre-drywall stage of construction, 100% of the ductwork and air handler shall be visible and visually verified to be contained inside the Conditioned Space Volume. At a final stage of construction, ductwork that is visible and the air handler shall again be verified to be contained in the Conditioned Space Volume.

• At a pre-drywall stage of construction, the ductwork shall be visually verified to be 100% fully ducted, with no building cavities used as supply or return ducts.