I would concure with this, Count.d, especially since my situation illustrates what you are saying perfectly.
We have a Wintergarden extension that was built three years ago using an aluminium frame and glass fasade system normally used for offices and larger building, the private sector is not the companies concern at all. However, the main reason for choosing this system (not necessarily the company) was because of the quality of the components and also because we needed 30min fire safety glass units in the roof.
In addition, we needed good insulation levels in the glass as there is quite a lot of it being a Wintergarden/facade system, and good sound insulation, as we are close to a 4 lane motorway. Here is the spec sheet for our glass in the roof as an example, (Contraflam 30 Climatop).
To get to my point, the problem we have is not related to the glass units themselves or the seals holding them to the aluminium frame but the aluminium frame door. The door height is 2.2m, the aluminium frame holding the triple glazed unit in place is 75mm thick, a very heavy door indeed. But despite that, there seems to be a very slight bow in the length of box aluminium down the side where the door latch is and even when the door latch is adjusted to try to achieve pressure between the door frame and the door when locking, there simply isn’t enough force in the locking mechanism to overcome this very slight bow. The result of this tiny gap (circa 3mm and 1m in length) is noise penetration all year round and heat loss during the cold periods. The door seems to be sealed fine everywhere else except along this 1m length of frame. Incredibly annoying.
It is currently -10 outside and we are heating the Wintergarden with electric underfloor folie heating which is struggling to get the room to 19 deg’s. I attach some photos for reference.
After some period of testing various gaskets, soft foam seals nothing has solved the problem because the door is sealed along the hinges anyway, and the area that needs attention is 3mm at the worst point (latch) going to 0mm at the top and bottom of the door, I need a very thin gasket that can also be compressed well.
Apart from the bow, which seems to be a mechanical defect in production, the door needs a much more robust locking system that is able to pull the door tight at three points, middle, top and bottom, the single one on our door is simply not man enough for the job.
My latest attempt now is to continue to search for the right gasket/seal (are you aware if these can be made to spec?) and I have ordered an upgrade to the single door latch from the manufacturer.
We see how it goes?
In conclusion - despite having high end specified triple glazed window units, the whole thing fails on energy and noise grounds because of a small defect in the door frame.
