HVAC Ductwork, Air Handling & Mechanical Products worked example

Leakage Test Rate at 99% pass rate acceptance target: a worked example

This scenario runs the leakage test rate calculation on the strong side: 99% pass rate acceptance target, with every other input held at its documented default. Use this when tracking leakage test results on fabricated duct sections, installed ductwork systems, or air handling unit casings. Pressurization testing per SMACNA standards confirms that joints and seams meet the specified leak class. Tracking the pass rate over time helps identify trends in seam quality, sealant application, or joint assembly issues before they accumulate on the job site.

The inputs for this scenario

  • Sections or zones that passed leakage test: 237 sections (unchanged)
  • Total sections or zones tested: 250 sections (unchanged)
  • Pass rate acceptance target: 99 % (raised for this scenario; the documented default is 95)

Working through the calculation

  • Applying the documented formula (Leakage test pass rate = sections passed รท total sections tested) to the inputs above produces each figure below.
  • At this operating point the engine returns 94.8 % for rate, the number this scenario is built around.
  • At this operating point the engine returns 4.2 points for gap to target.
  • At this operating point the engine returns 237 count for affected count.
  • At this operating point the engine returns 250 count for total count.

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. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Rate: 94.8 % (headline result)
  • Gap to target: 4.2 points
  • Affected count: 237 count
  • Total count: 250 count

Run it with your numbers

  • Every input above is editable in the live Leakage Test Rate calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.