Remove Grilles and Covers
Start by taking off all supply and return register grilles. This provides direct access for sealing and ensures no hidden leaks behind covers.
Securely Plug Each Opening
Use foam plugs, duct tape, or retrotec grill masking tape to seal each register tightly. Be thoroughāseal edges and any perforations to stop air from escaping or entering unwanted areas.
Confirm Full Coverage
Once taped, press each plug/sleeve gently. The seal should feel snug, with no gaps or squeaks. A proper seal prevents inaccurate leakage readings due to bypass airflow.
Optional Check with Pressure Pan
Use a pressure pan over each sealed register while pressurizing the duct. If pressure changes significantly, the seal needs reinforcing. This is a quick way to spot weak points before running the full test.
Why This Matters
| Issue | Effect on Leak Test |
|---|---|
| untaped registers | air bypass ā underestimates duct leakage |
| loose edges | creates inconsistent results between tests |
| adequately sealed | ensures reliability and repeatability |
