Blower Door Test and Leakage Detection - Experiences

  • Erstellt am 2011-11-06 13:17:30

BauherrCS

2011-11-06 13:17:30
  • #1
Hello everyone,

Despite searching, I unfortunately could not find an answer to my problem either on the major search engine or in this forum, so I now hope that I am in the right place here and that someone in this forum can help me.

Our construction project (single-family house) is now almost completed. We have now decided to have a blower door test and a leak detection carried out. The result is as follows:

The blower door test was successful (value 1.9 with 3.0 allowed). However, a leak detection performed revealed significant defects according to the expert.

Here is my first question: Can the BD test be positive despite leaks in the building envelope?

The leak detection was carried out as follows. A negative pressure was created inside the building and at several points outside the building smoke was generated with a handheld fog machine. Alarmingly, the smoke was drawn massively into the building. Among other places between the wall and floor, through the roller shutter box or under the window sills. Further measurements with a thermal anemometer showed values between 0.02 and 1.02.

In §6 of the [Energieeinsparverordnung] I found the following:

"Buildings to be constructed are to be executed so that the heat-transferring enclosing surface, including the joints, is permanently airtight sealed according to the recognized rules of technology. [...]"

As the only actually measurable value, I however only found the air change rate determined by the BD test in the regulation.

Therefore, besides the first question, I need help or answers regarding the following problems:

- Is there a defect if the BD test is okay but the leak detection is negative?
- How should I behave towards the construction company if they rely on the positive BD test?
- What does "permanently airtight sealed according to the recognized rules of technology" mean? Are the values possibly even within the standard range?

Sorry for the many questions, but the answers would really help me a lot.

Thank you very much.

Regards.
 

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