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matthiasl | 3 years ago
The best window I can find from the major Danish manufacturer Velfac has a total U-value of 0.82 W/°K/m² [1]. It's a triple-glazed window with argon and coatings.
A typical insulated thin (100mm) wood-frame wall, i.e. the sort you'd use if you were building a summer house in Sweden has a U-value of 0.4 W/°K/m² [2], i.e. twice as good as the window above.
A typical rock- or glasswool insulated wood-frame wall for a modern year-round house has a U-value of 0.2 W or better, i.e. four times as good as the window above.
Wall that are so bad that they're roughly equivalent to the triple-glazed window above are something you'll mainly find in buildings from 50+ years ago, at least in Sweden. I expect Norway to be similar. [3]
'bjarneh' mentioned both triple- and quadruple-glazed windows. I've only seen quadruple used in noise-reduction applications, e.g. hotel next to a busy road. If you have a data sheet for one, it'd be interesting to see what the U-value is.
One of the posters above referred to 'R-value'. It's the reciprocal of the U-value. Wikipedia has good explanations of both, as well as typical values for windows and walls. [4,5]
References are mostly in Swedish, because the poster 'bjarneh' was talking about windows in Norway, so I wanted references for companies that actually sell things in Scandinavia.
[1] https://products-api.velfac.com/files/11644/VELFAC%20STANDAR...
[2] https://www.isover.se/hur-tjock-isolering-ska-man-ha-att-fa-....
[3] https://www.traguiden.se/konstruktion/konstruktiv-utformning...
bjarneh|3 years ago
The ones we got for our house was ordered with noise reduction, but I think that basically just meant that they did not have that little valve at the top of the windows (ventil in Norwegain perhaps also in Sweedish?).
My situation is somewhat special since I have a very old house (built around 1850) made from a timber frame construction (timmerkoja in Sweedish I guess?). So the walls were extremely poorly insulated, basically just some wool (or something similar, not 100% sure what it was) between the beams as they were put on top of each other during the build. Regular boards where added on both sides of the timber frame, but no additional insulation until we renovated the house.
The 50 year old punctured double glaze windows - that came with the house were not doing too much in terms of insulation either.
Any insulated wall will probably be better than windows, but at least here in Norway, there are a bunch of old poorly insulated houses, with double glazed windows as most everyone got these things installed when they came out:
https://www.h-vinduet.com/
Husmorvinduet (housewife windows) was popular since they were so simple to clean; and electricity was cheap until quite recently I guess. But any wall with actual insulation will probably beat windows for insulation; although newer windows are not as terrible as the once were.
> so I wanted references for companies that actually sell things in Scandinavia
I guess they are manufactured elsewhere; but I think the ones we ordered was delivered from Røros-vindu, but I could not find any info about actual R/U-value for the windows on their website. Just some info about what types of gas they contain and so on.