5. Detection of existing leakages during the test
Surprisingly, not every (NSAI certified) air tightness tester is performing a leakage detection prior to the official depressurization & pressurization test. It´s clearly stated in paragraph
5.3.1 of the ISO 9972:2015, that such check of the building envelope is mandatory and detailed notes have to be taken about detected leakages.
6. Range of building pressures for an air tightness test
Many air tightness test reports come with the required quantity of induced pressure differences but the most of them have just readings for higher differential pressures. The air tightness test
standard is clearly setting the lowest limit for the data collection in paragraph 5.3.4: "The lowest pressure difference shall be approximately (i.e. with an allowance of ±3Pa) 10 Pa or five
times the value of the zero-flow pressure difference(ΔP01), whichever is greater."
It´s more difficult and time consuming to measure at lower pressure differences, that´s why some testers do finish their air tightness readings always at around 20-30 Pa differential pressure.
There´s plenty of options to manipulate an air tightness test, wittingly or unwittingly. It starts with wrong building dimensions and ends in manipulating the fan. I do not want to provide
details of how to manipulate an air tightness test, because every air tightness test is a formal procedure. There´s no advantage of having a better air tightness test result in the report
than in reality.
8. Official standard for air tightness testing
Here in Ireland, the mandatory standard for air tightness testing is
"I.S. EN ISO 9972:2015 - Thermal performance of buildings - Determination of air permeability of buildings - Fan pressurization method". The previous European norm EN 13829 for air tightness
testing is not longer valid for formal testing.
If you´re in need of an air tightness test or in case you might have doubts about details of an existing test, please feel free to get in contact with me, to discuss how you can be