Aluminium window condensation formation, missing insulation, improvement?

Hello,

in the rear wall area of a residential complex with the there-listed historic facade of a residential complex, aluminum windows with muntins were installed to meet the visual requirements of the former facade (presumably previously with delicate cast iron frames) of the windows, which has been successfully achieved. In the other newly constructed, non-monument-protected areas, wooden windows were installed.

In the cold season, there is strong condensation on the window panes of the installed aluminum windows in the sleeping areas, but also in the kitchen / living room area, while the also installed wooden windows in the non-monument-protected areas in the kitchen / living room area, which were newly built, show no condensation:



Other residents with windows in the monument-protected facade also have this problem, so I would assume that this is not due to (my) incorrect ventilation behavior (manual ventilation is performed regularly, and the decentralized ventilation for the individual rooms is additionally in operation).

Behind the monument-protected facade, a drywall installation was placed inside, which also has the probably necessary insulation layer. Here is the basic wall construction:



To bridge the gap between the massive exterior facade and the inner, insulated drywall construction, an aluminum profile was used without additional insulation / an insulation profile being applied. Here is the inner view of the wide profile between the window level / the exterior wall and the inner facing shell:



Here is a photo taken through an existing box of a decentralized ventilation system:



You can see that no insulation was used in the area of the aluminum cover profile ("window profile") between the outer wall and the drywall construction, which I would basically have expected here (the visible mud splashes come from the core drillings made in the outer wall for the installation of the decentralized ventilation units).

I therefore suspect that insulation is missing between the massive outer wall and the inner, insulated drywall construction in the area of the window connection, resulting in strong cooling at the surrounding aluminum profiles, which cool the entire window area (you can clearly feel the "cold draft" at the aluminum windows in winter, which is not the case with the wooden windows also installed in the kitchen / living room area).

My questions:
Is the installation of the windows without further insulation between the historic outer area and the installed drywall installation considered "professionally done," or should insulation profiles have been used around the window reveal here?

Would there be possibilities to improve the situation, for example by using construction / insulating foam that could be injected through drillings through and behind the drywall installation and thus between it and the outer wall?

Are there any other suggestions for optimization?

Thank you very much!

Best regards

Guido

Is there a vapor barrier or similar foil installed in the drywall? The condensation is on the glass, and I don’t believe that the glass cools down so much from the aluminum profile that the whole glass becomes cold; a warm edge will be installed. If it only comes from the profile, other areas would be affected, the profile itself and the sill.

What I will never understand.

You write a 20-line text with various assumptions, almost like a master's thesis, but somehow no one ever uses a moisture meter.

By the way, be glad that it is on the window and not on the wall. Because that is actually an indication that it is the room air.

We had the topic last winter.

https://www.hausbau-forum.de/threads/alu-holzfenster-3-fach-mit-kondensat-innen-trotz-warmerkante.38076/page-2#post-471387

...
You write a 20-line text with some assumptions, almost like a master's thesis,
...

If a master's thesis were that easy ... :)

With aluminum windows, there was this problem until the 1970s, which is related to the thermal conductivity of aluminum. Later, it was resolved by the fact that aluminum window profiles now basically consist of two half-shells, between whose outer and inner parts a separation is made by plastic strips. However, this applies to residential window profiles. Here, it seems to me that a fixed glazing has been installed instead in such a type of post-and-beam profiles, like those known from the entrance areas of hardware stores, furniture stores, and the like. However, these are technically more like cold conservatories. I consider it quite possible that these are still sometimes constructed as single-glazed.

Hello,

Nobody ever seems to use the humidity meter.

That is a valid objection; my description was indeed not detailed enough:
Actually, humidity meters were used: even in the open kitchen and living area, the humidity last winter did not exceed 60% (or if it did, only very briefly after cooking), it was rather around 50%. The condensation problem only occurs on the aluminum window in the kitchen, not on the wooden windows in the living area, although the humidity was measured as an average in the center of the open area.

In an unused room, the humidity with continuous decentralized ventilation last winter was consistently about 40-50%, but condensation also occurred there.

Is there a vapor barrier or similar foil installed in the drywall?
The condensation is on the glass, and I don’t think the glass cools down so much from the aluminum frame that the entire glass becomes cold; a warm edge spacer should have been installed.

I cannot say whether a vapor barrier was installed, since I took over the apartment. The attached photo of the inner construction of the wall and the aluminum profile / cover strip was taken while the decentralized ventilation system was dismantled for maintenance.

Regarding the "warm edge," I would need to read up on that, as I’m currently unsure what exactly that is.

In any case, I would have expected some kind of "insulation block" between the solid exterior wall and the added drywall around the installed window, but nothing like that is installed. In the photo, you can see directly the "aluminum bridging profile," which bridges the cavity.

With aluminum windows, there was this problem until the 1970s, related to the thermal conductivity of aluminum. Later it was resolved by making aluminum window profiles out of two half-shells, separated on the inside and outside by plastic spacers. However, that applies to residential window profiles. Here, it seems to me instead that a fixed glazing has been installed in this type of mullion-transom profile, like you see in entrance areas of hardware stores, furniture stores, and the like. Technically these are more like cold winter gardens. I consider it quite possible that these are sometimes still constructed as single-pane.

The residential complex was built in 2007, the windows are from Schüco; I cannot say exactly how they are constructed. Since I am currently traveling, I can only upload further photos over the weekend.

Many thanks!

Best regards

Guido