Residential Envelope Testing
Target Rate: ā¤āÆ3āÆACH50 (air changes per hour at 50āÆPa) for detached homes using the prescriptive path.
Performance Path: Allows up to 5āÆACH50 if offset by other energy measures; alternatively, use 0.3āÆCFM per ftĀ² of enclosure area in small or attached homes.
When to test: Postāconstruction, before drywall, and again at final for verification. Early “preāseal” checks help avoid failures.
Duct Leakage Testing
Now required in IECCāÆ2021 even if ducts/air handler are inside the thermal envelopeāexception removed from previous versions.
Acceptable leakage:
ā¤āÆ8āÆCFM25/100āÆftĀ² conditioned area if inside the envelope.
ā¤āÆ4āÆCFM25/100āÆftĀ² if outside.
Test pressure: Ā±25āÆPa (or 50āÆPa 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 ānext testing requirements.ā
Compliance with WiFi Gauges & Apps
DMā32 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.
Whatās Next in Codes
More widespread sampling protocols expected in multi-family buildingsāe.g., test 20% of units.
Increasing reliance on verification before testing, especially in commercial envelope compliance.
Possible new IECC requirements for overall system performanceālike air-sealing quality or balanced ventilation checks.
Action Plan Checklist
| Task | Target | When |
|---|---|---|
| Blower door envelope test | ā¤āÆ3āÆACH50 (or 5/0.3) | Final construction stage, post-drywall |
| Duct leakage test | ā¤āÆ8 CFM25 inside or ā¤āÆ4 CFM25 outside | Rough-in or final |
| Exhaust airflow verification | Per ASHRAE 62.2 | Post-install, before occupancy |
| Use DMā32 WiFi gauge + apps | Auto-logged, documented | During each test |
| Plan for sampling in multiāfamily | ā„āÆ20% of units | Future code cycles |
| Consider envelope plan reviews | Before sheetrock | To reduce risk of failure |
