Conference Agenda

Session
PS-03: Airtightness Applications, Repeatability, and Lessons Learned
Time:
Wednesday, 24/Sept/2025:
9:30am - 10:30am

Location: Ravel


Presentations

How Precise is Airtightness Testing? Exploring Repeatability, Reproducibility, and Uncertainty Quantification

Martin Prignon1, Ben Roberts2, Liesje Van Gelder3, Maarten De Strycker3, Jiri Novak4

1Buildwise, Belgium; 2Loughborough University, UK; 3BCCA, Belgium; 4CTU Prague, Czech Republic

This study addresses two key challenges related to uncertainty assessment in fan pressurization measurements: (1) estimating the typical precision error (general approach), and (2) providing a rigorous framework for uncertainty calculation in individual tests (specific approach). The general approach is investigated through the analysis of multiple repeatability and reproducibility studies, including two new datasets reported by the authors. The specific approach is assessed by applying and comparing different uncertainty propagation frameworks on two controlled datasets.

For the general approach, results indicate a precision error of 1-2% for the measurement method itself, 2-3% when different experienced operators conduct the test without preparing the building, 4% when operators also prepare the building but with external verification, and up to 20% when no verification is performed, or with unexperienced operators. However, the limited availability of reproducibility data restricts the generalizability of these findings.

For the specific approach, results show that all tested procedures perform similarly at 50 Pa (0.2 in.) in terms of both observed and estimated uncertainty. At 4 Pa (0.016 in.), all weighted procedures reduce the precision error compared to the unweighted ISO method. Based on these results, the authors recommend the WLOC procedure with newly proposed weights, as it is fully based on the GUM framework, supported by dedicated studies, and applicable even when equipment specifications are unknown or when only single-point measurements are available at each pressure station.