Key IECC 2021 Requirements
| Test Type | Requirement | When to Perform |
|---|---|---|
| Envelope Test | ≤ 3 ACH50 (or ≤ 5 ACH50/performance path) | After drywall/final trim |
| Duct Leakage | ≤ 8 CFM25/100 ft² if inside; ≤ 4 CFM25/100 ft² if outside | Rough-in or final stage |
| Ventilation Flow | Verify per ASHRAE 62.2 (using flow pans or pressure matching) | At final inspection |
Top Items to Guarantee Passing
Seal early: Walls and ductwork should be air-sealed before covering.
Pre-test before drywall: Catch issues early—address leaks before finishing.
Validate test prep: Ensure HVAC systems are off, registers sealed, duct seals confirmed.
Use correct pressure settings: Blower door at 50 Pa; duct leaks at ±25 Pa.
Check outliers: Sampling will likely be enforced, especially in multi-family and commercial applications.
Smart Tools Compliance
DM‑32 WiFi gauge: Supports remote control, data export (CSV/Excel), and app integration.
Virtual Gauge & GaugeRemote: Allow real-time, remote management—perfect during multi-site testing.
Data Logger: Logs channel A/B data automatically—excellent for reporting and compliance auditing.
What’s Next in Testing Requirements
Expanded sampling protocols: Expect larger system testing—initially 25%, then 50% or full system testing if failure is detected (per ASHRAE 90.1 updates).
New duct insulation rules: All ducts outside conditioned spaces need at least R‑8 (zones 0–4) or R‑12 (zones 5–8) insulation.
Enhanced envelope verification: More emphasis on pre‑sheetrock air-sealing and energy plan reviews to reduce test failures.
Broad code enforcement: Both residential and commercial buildings will face stricter oversight and mandatory testing samples.
