Luft.Ort.Leck: Localized leakages – method and probe development

The airtightness or air permeability can currently only be determined as sum parameter for the entire building by means of blower door measurement or for the individual component, e.g. a window on the test bench. The blower door measurement, also called differential pressure measuring method, is carried out in accordance with ÖNORM EN ISO 9972. For standard buildings n₅₀ ≤ 3.0/h, for buildings with a mechanical ventilation system n₅₀ ≤ 1.5/h and for passive houses n₅₀ ≤ 0.6/h have been established as limit values for the sum parameter n₅₀ value. An n₅₀ value of e.g. 3.0/h means that at 50 Pa pressure difference the air volume of the building is exchanged three times per hour.

A limit for the individual local leakage in building components does not exist. In the course of the blower door measurement, according to the standard, leak detection must also be carried out, for example through smoke, by expert’s hand, measuring the air velocity, whereby, however, a quantification of the leakage volume is currently only subjective by the expert.

The significant improvement of the methodology, product development and quality assurance for buildings and building components is the overall objective of this project with the following specific targets:

• A new facility can measure individual local leaks.
• A new, mobile probe enables the detection and
• quantification of local leakages on the construction site and on the test bench.
• The acquired know-how serves as the basis for at least one follow-up project and for the development of a new test standard.

At the beginning of the project, a test bench is purchased. In the next step, a mobile measuring probe for leak location and measurement will be developed and its practicability, accuracy and reproducibility will be validated and calibrated with the help of the test bench. In the course of this, different measuring principles (for example hot-wire anemometers, vane anemometer, LFE, etc.) will be compared and further developed. In the final step, the use of the mobile probe will be checked in the research building of HFA, on the component test bench of BTI, in the ACR test boxes of AEE INTEC and on the construction site in combination with the blower door measurement.

Thus, there will be a range of services offered by the three ACR institutes for product development and quality assurance to the target group of SMEs – building contractors, developers, real estate developers and technical offices.