ᐅ Mounting the ventilation ducts of the controlled residential ventilation system on the flat duct manifold

Hello everyone,

Since the ventilation ducts have already been damaged in several places, I’ve looked into the issue more closely. I noticed that all the ducts are fixed to the flat distribution box in the concrete ceiling using self-tapping screws. Unfortunately, I haven’t been able to find out which manufacturer was installed so that I could research further. In general, I would say that screw heads have no place inside a ventilation duct.

Attached are a few photos. Could you give me some keywords or suggestions on how to find out more about this? I don’t want to approach the general contractor with a suspicion just yet; I want to be absolutely sure myself first whether this is unacceptable.

Thanks in advance for your assessment.

What kind of suspicion? In any pipe, regardless of the medium—gas, water, air, sewage, oil, sludge, semolina, or pizza sauce—there should never be any narrowing caused intentionally by people who often have poor judgment.

Over time, though usually quite quickly, dust will accumulate there. Dust attracts more dust; this is basically a fundamental law of dust. Then it becomes moist because your humid indoor air is being blown through. The dust takes advantage of this and starts inviting its friend, mold...

Is there even the slightest chance to remove these screws afterward? If yes, then do it. Now...

It MAY be allowed in some cases to attach the ventilation duct to the manifold with screws (larger spiral-wound ducts, etc.). However, I don’t see any pictures. If I had them, I could ask an MEP planner (in the family).

i_b_n_a_n schrieb:

It MAY be permitted in some cases to fasten ventilation ducts to the manifold using screws (larger spiral ducts, etc.), but unfortunately, I don’t see any pictures. If I had them, I could ask an HVAC planner (in the family).

I attached three pictures to my post; are they not visible? I can see them myself.

I can see them now too, strange. Sometimes the forum behaves oddly...
At first glance, it doesn’t look compliant to me...

Usually, there are rings or seals that go around the pipes and then click into place at the appropriate position. This seals and secures the pipe against the valve or manifold.

I’ll ask around...

Regarding the screws, the MEP planner says: It looks unacceptable, probably not watertight against the mixing water from the concrete.
As the site manager, he would not have approved this type of fastening. ;-)

But he also says: When in doubt, consult the manufacturer regarding approval.