All Ducts Fully Ducted
All HVAC ducts are fully ducted — none panned in joists.
Spec
Applies uniformly from Platinum upward.
Scope
All HVAC supply and return ductwork in the dwelling — new and existing.
Requirements
- 01.
Every duct in the HVAC system must be fully ducted (rigid metal or insulated flex). No panned joist returns, building-cavity returns, or wall-stud-bay supplies.
- 02.
All duct joints sealed with UL-181 rated mastic or tape.
- 03.
Duct leakage test must show ≤ 4 CFM25 per 100 sf of conditioned floor area (or stricter local code).
Documentation
Evidence the inspector / Institute will need.
- 01.
Duct leakage test report from a certified tester showing total system leakage in CFM25.
- 02.
Photos of representative duct runs showing all-rigid or all-flex construction.
- 03.
For renovation: marked-up plan showing replaced/rebuilt ducts where panned cavities were removed.
Guidance
Why this is Platinum-only
Retrofitting fully-ducted returns in an existing house with panned-joist returns is invasive — typically requires removing some ceiling drywall to install new round flex. New construction is straightforward. Platinum tier reflects the level of envelope discipline required to actually achieve this end-state.
Resources
- ASHRAE 152 — Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems
The protocol behind duct leakage testing.