5 ms·

In triple and quadruple glazing, you frequently don't get three or four layers of actual glass. The two outer layers are still glass, but the inner layers are u

In triple and quadruple glazing, you frequently don't get three or four layers of actual glass. The two outer layers are still glass, but the inner layers are usually thin sheets of plastic, and the voids are frequently filled with noble gasses like Argon for improved insulation. Although I have seen in Alaska where they do double glazing windows on the outside as storm windows, then about six inches to a foot inside of that, they have another layer of double glazing. Yes, the walls are super thick.

gambiting 4y ago
>>and the voids are frequently filled with noble gasses like Argon for improved insulation. How long is such a window rated for? Surely the gas will eventually leak out?
- skipnup 4y ago
  Not really a problem one would be aware of. Double glazing is the default since 50 years at least in Germany, so the manufacturing processes are quite good. Still, leakages happen, you recognize that usually by water/steam between the two glass panes. If the windows aren't to old you can just switch out the glass leaving the plastic frames. If they're older (30 yrs) it's more economical to switch out glass and frames.
  - toyg 4y ago
    Almost all my double glazed windows have now failed and I'm looking at replacements, but my fear is that the failures are due to the amount of vibrations this house gets (I'm close to a busy road, every time a lorry goes past I can feel it in some rooms).
- morsch 4y ago
  From what I can find, the leakage is estimated at < 1% per year. This (German) discussion references and quotes the (German) industry standard DIN EN 1279-3. https://www.haustechnikdialog.de/Forum/t/65875/Haltbarkeit-Argonfuellung-in-Isolierfenstern- https://www.haustechnikdialog.de/Forum/t/65875/Haltbarkeit-A...
- Retric 4y ago
  Leakage rate is ~1% per year. However the gas isn’t so important you need to replace the window as argon is only up to 16% better than air. It’s worth it to manufacture windows like this, but unless you’re in the arctic circle I wouldn’t worry about the difference.
  - thedougd 4y ago
    There’s been so many window manufacturer lawsuits over this issue that my guess is a manufacturing defect.
- bradknowles 4y ago
  Properly constructed, I think these windows are expected to have a useful lifespan of at least 20-30 years. I think the heavier gasses are less likely to leak, so long as the window is kept intact and undamaged.
bloak 4y ago
I'd expect the insulating properties of a gas at normal temperatures and pressures to depend only on the molecular mass. That's 40 for argon, and 28 for nitrogen. This web page (https://www.pressglass.com/noble-gases-and-thermal-insulation-in-windows/ https://www.pressglass.com/noble-gases-and-thermal-insulatio...) says the thermal conductivities are 0,026 W/(mK) for air and 0,018 W/(mK) for argon. 26/18 is about 1.44; 40/28 is about 1.43. So perhaps the conductivity is inversely proportional to the molecular mass? In that's true then it's not a "noble" gas you want for improved insulation, but a dense gas (so not helium). You should be using tungsten hexafluoride! OK, not really: see https://en.wikipedia.org/wiki/Tungsten_hexafluoride https://en.wikipedia.org/wiki/Tungsten_hexafluoride for why not.
- tlb 4y ago
  The heat capacity of the gas depends on both mass and molecular structure. Atoms like argon have no structure, but molecules like O2 and N2 carry extra heat energy in their vibrating bond, so they have more heat capacity per unit mass.
  - bloak 4y ago
    That's a good point. Perhaps the result of that argon/nitrogen comparison was a coincidence, or perhaps heat capacity doesn't much affect thermal conductivity. Here's an argument that heat capacity shouldn't affect thermal conductivity in a solid: imagine a block of material with a smooth temperature gradient through it and the temperature at any point remaining constant, so there is heat flowing through it. Now imagine you have some tiny beads of some other material with a super-high heat capacity. Distribute those beads throughout the block of material, preheating each bead to the correct local temperature before inserting it. Then intuitively it seems that neither any local temperature nor the rate of flow of heat through the block should change much. Yet the heat capacity of the new composite material is significantly higher than that of the original material. Does that argument make sense? I did physics at school but not since then!
    - tlb 4y ago
      Yes, I don't think they're strongly related in a solid. But in a gas, heat transfer is mostly driven by convection. Gas near the hot surface heats up, rises, moves to the cold surface, falls, and repeats. So what matters is the specific heat capacity * the flow rate between hot and cold surfaces.
joris 4y ago
That probably depends on where you are. Here in Amsterdam, our triple glazing is made out of all actual glass. In our house it’s made out of four 6-mm sheets of glass actually. So one double sheet that’s a sandwich with a glued layer of foil in between (like a windshield), used as a security component either on the outside (anti break-in) or on the upper floors on the inside as a way to prevent falling through the window.
- HPsquared 4y ago
  Having more layers of actual glass helps with sound insulation also, probably more of a concern in Amsterdam than in Norway.
- actionfromafar 4y ago
  6mm sounds very thick?
  - eitally 4y ago
    Probably meant 6 mil (1mil = 1 thousandth of an inch), since this is a typical non-metric measure of sheet thickness (metal, glass, plastic).
- bradknowles 4y ago
  Yeah, I'm sure it does depend on where you are. For the nearly eight years that my wife and I lived in Brussels, Belgium, we lived in an old house (rented) that was built around 1910, and so we didn't have even double glazing, although we did have French Doors, and we had custom-made screens that had to be manually placed into the windows and then pinned in place with a nail instead of always attached to the outside. So, I don't have much knowledge of what current European building standards are in this space. I do prefer the German-style double-opening windows that I saw in the house my sister-in-law was renting near Spangdalem AFB, along with the Rolladen that they had installed. But again, that was a rental in an older home. I have been watching Laura Kampf and her "Haus Lise Lotte" project on YouTube, but again that's a 120 year old house, and they haven't gotten to replacing the windows yet. Any suggestions for an English language channel where I could learn more about current European building standards, maybe something like Matt Risinger's "Build Show" for US building standards that I've been watching on YouTube?
dan-robertson 4y ago
Somehow I’d thought the voids were usually evacuated but that doesn’t really make sense with the pressure involved. Apparently it is possible to have a vacuum inside but uncommon and harder to manufacture (and you need support pillars to separate the panes). https://www.glassonweb.com/article/vacuum-insulating-glass-past-present-and-prognosis https://www.glassonweb.com/article/vacuum-insulating-glass-p...
- HPsquared 4y ago
  You'd still have radiative heat transfer, even if there is a vacuum between the panes. For a given budget, you're probably better off adding more regular panes.
  - dan-robertson 4y ago
    Aren’t new windows often coated with something opaque to IR, that way they keep heat in during winter and don’t heat up like a greenhouse in the summer?
    - HPsquared 4y ago
      Those are low-emissivity coatings. Very effective in reducing radiative heat transfer. This is why the glass in a vacuum flask is silvered: metals have low emissivity. These coatings aim to have low IR emissivity while still allowing visible light through (IR light gets reflected, instead of absorbed/emitted). My point was only that a vacuum gap is still not a perfect insulator, so it's an economic trade-off.

gambiting 4y ago

>>and the voids are frequently filled with noble gasses like Argon for improved insulation. How long is such a window rated for? Surely the gas will eventually leak out?

skipnup 4y ago
Not really a problem one would be aware of. Double glazing is the default since 50 years at least in Germany, so the manufacturing processes are quite good. Still, leakages happen, you recognize that usually by water/steam between the two glass panes. If the windows aren't to old you can just switch out the glass leaving the plastic frames. If they're older (30 yrs) it's more economical to switch out glass and frames.
- toyg 4y ago
  Almost all my double glazed windows have now failed and I'm looking at replacements, but my fear is that the failures are due to the amount of vibrations this house gets (I'm close to a busy road, every time a lorry goes past I can feel it in some rooms).
morsch 4y ago
From what I can find, the leakage is estimated at < 1% per year. This (German) discussion references and quotes the (German) industry standard DIN EN 1279-3. https://www.haustechnikdialog.de/Forum/t/65875/Haltbarkeit-Argonfuellung-in-Isolierfenstern- https://www.haustechnikdialog.de/Forum/t/65875/Haltbarkeit-A...
Retric 4y ago
Leakage rate is ~1% per year. However the gas isn’t so important you need to replace the window as argon is only up to 16% better than air. It’s worth it to manufacture windows like this, but unless you’re in the arctic circle I wouldn’t worry about the difference.
- thedougd 4y ago
  There’s been so many window manufacturer lawsuits over this issue that my guess is a manufacturing defect.
bradknowles 4y ago
Properly constructed, I think these windows are expected to have a useful lifespan of at least 20-30 years. I think the heavier gasses are less likely to leak, so long as the window is kept intact and undamaged.

bloak 4y ago

I'd expect the insulating properties of a gas at normal temperatures and pressures to depend only on the molecular mass. That's 40 for argon, and 28 for nitrogen. This web page (https://www.pressglass.com/noble-gases-and-thermal-insulation-in-windows/ https://www.pressglass.com/noble-gases-and-thermal-insulatio...) says the thermal conductivities are 0,026 W/(mK) for air and 0,018 W/(mK) for argon. 26/18 is about 1.44; 40/28 is about 1.43. So perhaps the conductivity is inversely proportional to the molecular mass? In that's true then it's not a "noble" gas you want for improved insulation, but a dense gas (so not helium). You should be using tungsten hexafluoride! OK, not really: see https://en.wikipedia.org/wiki/Tungsten_hexafluoride https://en.wikipedia.org/wiki/Tungsten_hexafluoride for why not.

tlb 4y ago
The heat capacity of the gas depends on both mass and molecular structure. Atoms like argon have no structure, but molecules like O2 and N2 carry extra heat energy in their vibrating bond, so they have more heat capacity per unit mass.
- bloak 4y ago
  That's a good point. Perhaps the result of that argon/nitrogen comparison was a coincidence, or perhaps heat capacity doesn't much affect thermal conductivity. Here's an argument that heat capacity shouldn't affect thermal conductivity in a solid: imagine a block of material with a smooth temperature gradient through it and the temperature at any point remaining constant, so there is heat flowing through it. Now imagine you have some tiny beads of some other material with a super-high heat capacity. Distribute those beads throughout the block of material, preheating each bead to the correct local temperature before inserting it. Then intuitively it seems that neither any local temperature nor the rate of flow of heat through the block should change much. Yet the heat capacity of the new composite material is significantly higher than that of the original material. Does that argument make sense? I did physics at school but not since then!
  - tlb 4y ago
    Yes, I don't think they're strongly related in a solid. But in a gas, heat transfer is mostly driven by convection. Gas near the hot surface heats up, rises, moves to the cold surface, falls, and repeats. So what matters is the specific heat capacity * the flow rate between hot and cold surfaces.

joris 4y ago

That probably depends on where you are. Here in Amsterdam, our triple glazing is made out of all actual glass. In our house it’s made out of four 6-mm sheets of glass actually. So one double sheet that’s a sandwich with a glued layer of foil in between (like a windshield), used as a security component either on the outside (anti break-in) or on the upper floors on the inside as a way to prevent falling through the window.

HPsquared 4y ago
Having more layers of actual glass helps with sound insulation also, probably more of a concern in Amsterdam than in Norway.
actionfromafar 4y ago
6mm sounds very thick?
- eitally 4y ago
  Probably meant 6 mil (1mil = 1 thousandth of an inch), since this is a typical non-metric measure of sheet thickness (metal, glass, plastic).
bradknowles 4y ago
Yeah, I'm sure it does depend on where you are. For the nearly eight years that my wife and I lived in Brussels, Belgium, we lived in an old house (rented) that was built around 1910, and so we didn't have even double glazing, although we did have French Doors, and we had custom-made screens that had to be manually placed into the windows and then pinned in place with a nail instead of always attached to the outside. So, I don't have much knowledge of what current European building standards are in this space. I do prefer the German-style double-opening windows that I saw in the house my sister-in-law was renting near Spangdalem AFB, along with the Rolladen that they had installed. But again, that was a rental in an older home. I have been watching Laura Kampf and her "Haus Lise Lotte" project on YouTube, but again that's a 120 year old house, and they haven't gotten to replacing the windows yet. Any suggestions for an English language channel where I could learn more about current European building standards, maybe something like Matt Risinger's "Build Show" for US building standards that I've been watching on YouTube?

dan-robertson 4y ago

Somehow I’d thought the voids were usually evacuated but that doesn’t really make sense with the pressure involved. Apparently it is possible to have a vacuum inside but uncommon and harder to manufacture (and you need support pillars to separate the panes). https://www.glassonweb.com/article/vacuum-insulating-glass-past-present-and-prognosis https://www.glassonweb.com/article/vacuum-insulating-glass-p...

HPsquared 4y ago
You'd still have radiative heat transfer, even if there is a vacuum between the panes. For a given budget, you're probably better off adding more regular panes.
- dan-robertson 4y ago
  Aren’t new windows often coated with something opaque to IR, that way they keep heat in during winter and don’t heat up like a greenhouse in the summer?
  - HPsquared 4y ago
    Those are low-emissivity coatings. Very effective in reducing radiative heat transfer. This is why the glass in a vacuum flask is silvered: metals have low emissivity. These coatings aim to have low IR emissivity while still allowing visible light through (IR light gets reflected, instead of absorbed/emitted). My point was only that a vacuum gap is still not a perfect insulator, so it's an economic trade-off.