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

Allthewayup schrieb:

As I said, unfortunately I don’t know the manufacturer, so I’m basically guessing whether this is actually completely unacceptable.

I would ask the installer to prove the correct fastening according to the manufacturer’s instructions, even if you now know that this is not the case.

I can’t change the situation at this point, so I’ll avoid adding fuel to the fire because I want the house to be finished eventually. Once the manufacturer has (hopefully clearly) responded, I will bring up the issue again and insist on a "compensation proposal" from the general contractor before settling the final payment (the installer is not my direct contact). Technically, beyond cutting off the screws with a rotary tool, there’s probably not much more that can be done. Whether this will cause any significant disadvantages regarding operation, hygiene, durability, etc., should then be clarified by the expert. If not, at least I can say I maintained my position. There are also a few other problem areas where the indicator clearly points to "botched work." I don’t want to burden the atmosphere with potentially solvable issues throughout, even though I would prefer otherwise. What I wanted to achieve with this thread, I have accomplished: input from the manufacturer and suggestions regarding my problem—thanks to everyone for that. I will keep you updated on what Fränkische says about fastening with screws.

I just spoke with Technical Support.

According to the manufacturer, the pipes are secured by fully inserting them, so they basically snap into place. Fixing them with screws is not necessary. At the moment, this is not considered critical for the system’s current state, since there is a filter in every air inlet that prevents dust from entering the system at all. It’s a different story when it comes to cleaning the system. Special tools are used for that, which no longer fit into the pipe because the screws are in the way. Additionally, the system is designed to be neutral (surfaces, odors, etc.). The galvanized steel screws simply don’t fit into that concept. Not that you would smell them or anything like that, but they now represent a potential weak point in the system. As expected, the only option will be to slightly conceal them (cut off the screws), but that won’t undo the issue.

I need to sort this out for myself first and consider how and when to raise the issue. The goal should be to enable future cleaning (so all screws must be cut off) and to cover the slightly increased risk of another damage event (e.g., screw remnants beginning to corrode). According to the technician, any kind of chemicals have no place inside the pipes, especially regarding sealing screw remnants with resin.

Really frustrating stuff :-/

Is cutting really that beneficial?
Doesn't it introduce metal shavings and could the screws rust because the galvanization is damaged?

RotorMotor schrieb:

Is cutting off really that beneficial?
Doesn’t it introduce metal shavings and could the screws rust because the galvanizing is damaged?

You could also leave the screws as they are until the ducts need or should be cleaned. That might be in 5 years or even 20 years. Cutting them off is definitely not ideal, but if the ducts are ever going to be cleaned, it’s probably unavoidable. I’m not sure what’s better right now. Cut them off now and see what happens in 4 years (warranty period) or leave them as is (never change a running system). The metal shavings could be vacuumed out since the screws are about 5–7cm (2–3 inches) away from the outlet. You can see the screws with the naked eye from below.

I just checked part of the ventilation ducts with my inspection camera and found an additional drill hole damage near the air distribution box. Couldn’t get any better :-D