HVAC Ductwork, Air Handling & Mechanical Products worked example

Leakage Test Rate at 68% pass rate acceptance target: a worked example

This worked example runs the leakage test rate numbers for a tougher week than the baseline: 68% pass rate acceptance target instead of the typical 95%. Calculate the duct leakage test pass rate for fabricated or installed ductwork sections. Compare the number of sections that pass pressurization testing to the total tested, and check the gap against your acceptance target.

The inputs for this scenario

  • Sections or zones that passed leakage test: 237 sections (held at the documented default)
  • Total sections or zones tested: 250 sections (held at the documented default)
  • Pass rate acceptance target: 68 % (the input this scenario stresses; the baseline uses 95)

Working through the calculation

  • The calculation starts from the formula this tool documents: Leakage test pass rate = sections passed รท total sections tested.
  • Rate works out to 94.8 % at these inputs, and this is the headline figure for the scenario.
  • Gap to target works out to -26.8 points at these inputs.
  • Affected count works out to 237 count at these inputs.
  • Total count works out to 250 count at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where pass rate acceptance target sits at 95% and the headline result is 94.8 %, this scenario lands almost exactly on the baseline at 94.8 %.
  • Use it during commissioning or QA signoff to certify duct leakage performance and to decide whether re-sealing and retesting are required. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Rate: 94.8 % (headline result)
  • Gap to target: -26.8 points
  • Affected count: 237 count
  • Total count: 250 count

Run it with your numbers

  • To rerun this with your own numbers, open the live Leakage Test Rate calculator, set pass rate acceptance target to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.