Controlled residential ventilation - ventilation duct - screws protrude into the duct!!!

Hello everyone,

I had a house built through a property developer. A controlled residential ventilation system with heat recovery was integrated into the insulation layer. The ventilation ducts are made of galvanized steel in flat duct design.

Now, after the completion of the house, I wanted to vacuum the ducts, as quite a bit of dust had accumulated, and I had to realize that at every joint between two pipes several screws protrude into the ventilation duct. This makes it almost impossible to insert the vacuum hose; I almost could not get it out again.

According to inquiries to the installing company, fastening of flat ducts/ventilation pipes with self-drilling screws is completely normal and permissible.

In my opinion, this makes it impossible to ever clean the duct and thus represents a huge defect.

Are there any rules, standards, or similar regarding this?

Does anyone have a similar problem?

Thank you very much for the help.

Thomas.

Hello Thomas,

A controlled residential ventilation system with heat recovery was integrated into the insulation layer. The ventilation ducts are made of galvanized steel in flat duct design.

Which manufacturer was installed? Unless it is a rather unknown manufacturer, they should be able to give you reliable information.

Best regards from the Rhineland

The controlled residential ventilation system is a Vallox Plus350. However, the pipes were not used by the manufacturer because the floor construction was too low and therefore shallower flat duct/spiral seam pipes were used. I have already contacted Vallox / Heinemann about this, but so far without success; no one was able to help me on the phone either.

Regards, Thomas.

Do the ducts really have to be cleaned regularly? For the exhaust air it doesn't matter anyway since it goes outside. For the supply air, you only have the remnants from the construction in the ducts (why did something get in there? Actually, the openings are sealed until they are connected to the system, so the pipes stay really clean - that was the case for us), fresh air runs through the filters in the system.

Well, I've also wondered whether I ever actually have to deal with that, but if you research online, it says that you should clean the pipes every few years. And knowing my wife, if a spider, spiderweb, or whatever moves in there, the vacuum cleaner will be plugged in.

Somehow the pipe elements must be fixed to each other, otherwise there is a high risk that they will be pulled apart in the course of the work (filling, screed). Yes, the pipe systems should be cleaned regularly, (especially on the exhaust side), otherwise deposits form due to the low speeds (higher speeds would be an acoustic problem) and thus the pipes clog over time. For round systems, a corresponding "ball" is usually sucked through to carry everything along. In the system I installed, the pipes hold due to the seals on the sockets, and immediately afterwards they are fastened with a nail strip. This way, there are no screws protruding inside the small pipes. For the large round pipes, however, for example with the Lindab "Safe" system, there is the instruction to set a certain number of screws or rivets depending on the diameter. I hardly believe that "cleaning" means what you can achieve with your vacuum cleaner, but rather what specialized companies do.