Residential Envelope Testing
Target Rate: ≤ 3 ACH50 (air changes per hour at 50 Pa) for detached homes using the prescriptive path.
Performance Path: Allows up to 5 ACH50 if offset by other energy measures; alternatively, use 0.3 CFM per ft² of enclosure area in small or attached homes.
When to test: Post‑construction, before drywall, and again at final for verification. Early “pre‑seal” checks help avoid failures.
Duct Leakage Testing
Now required in IECC 2021 even if ducts/air handler are inside the thermal envelope—exception removed from previous versions.
Acceptable leakage:
≤ 8 CFM25/100 ft² conditioned area if inside the envelope.
≤ 4 CFM25/100 ft² if outside.
Test pressure: ±25 Pa (or 50 Pa where applicable), following accepted protocols using DucTester or similar.
Exhaust/Ventilation Testing
IECC encourages verifying exhaust systems (bath fans, range hoods) using flow pan, flow hood, or pressure-based tools like FlowFinder or DucTester.
No universal CFM limit provided in IECC, but ASHRAE 62.2 guidance contributes to “next testing requirements.”
Compliance with WiFi Gauges & Apps
DM‑32 with WiFi/Ethernet supports remote control, data logging (Excel/CSV), and app-based workflows, aligning with documentation best practices.
Tools like Virtual Gauge, GaugeRemote, and Data Logger can confirm test accuracy and speed up reporting.
What’s Next in Codes
More widespread sampling protocols expected in multi-family buildings—e.g., test 20% of units.
Increasing reliance on verification before testing, especially in commercial envelope compliance.
Possible new IECC requirements for overall system performance—like air-sealing quality or balanced ventilation checks.
Action Plan Checklist
| Task | Target | When |
|---|---|---|
| Blower door envelope test | ≤ 3 ACH50 (or 5/0.3) | Final construction stage, post-drywall |
| Duct leakage test | ≤ 8 CFM25 inside or ≤ 4 CFM25 outside | Rough-in or final |
| Exhaust airflow verification | Per ASHRAE 62.2 | Post-install, before occupancy |
| Use DM‑32 WiFi gauge + apps | Auto-logged, documented | During each test |
| Plan for sampling in multi‑family | ≥ 20% of units | Future code cycles |
| Consider envelope plan reviews | Before sheetrock | To reduce risk of failure |
