ZI-720 Air-tightness RD and RRD

The “TÜV NORD” certificate confirms that the airtightness of the METU RD and GX access doors is much lower than the admissible leakage of the highest airtightness class D (DIN EN 1507 / ATC2 EN 16798-3), assuming the access doors have been properly installed according to our instructions.

One should especially make sure that:

  • the knobs are sufficiently tightened (F > ≈ 500 N)
  • the access door is installed on a smooth and clean surface

Given these performances it can be assumed that the D class is also reached by the RRD access doors (for circular ducts).