6 ms·

TIL quadruple glazing is a thing. Is the light noticeably more attenuated through 4 panes of glass compared to 2 or 3?

by ssl232 4y ago

bestham 4y ago
It is really hard to tell when every window is of the same dampening. But yes, I guess they lose some light.
bjarneh 4y ago
> Is the light noticeably more attenuated through 4 panes of glass compared to 2 or 3? I don't notice a difference now that I have two double glazed windows on top of each other (kobla vindu - I don't know the English word for it), I'll include a picture here: https://spesialvinduer.no/wp-content/uploads/2019/08/Skaara_koblet-vindu-8734-Edit-3-kopi.jpg https://spesialvinduer.no/wp-content/uploads/2019/08/Skaara_...
- poooogles 4y ago
  >kobla vindu - I don't know the English word for it) In the UK we'd call this secondary glazing if I'm understanding the image correctly.
  - bjarneh 4y ago
    OK, an absolute nightmare to clean though. 4 surfaces on each window; and dirt/insects etc. can sneak into the space between the windows. But they look old cool and authentic I guess :-)
bradknowles 4y ago
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
empiricus 4y ago
It is a little worse than that: some triple glazed windows are intentionally made more opaque/green tint for 2 reasons: 1. easier on the eye when sunny outside, and 2. block up to half of solar radiation, to prevent overheating indoors
- bryanrasmussen 4y ago
  does Norway worry about overheating indoors though?
  - ptman 4y ago
    I'm not in Norway, but here in Finland I don't appreciate having nearly 30C indoors in the summer.
  - antipotoad 4y ago
    Not sure, but consider that summer months can have little to no nighttime owing to the northerly latitude.
    - bryanrasmussen 4y ago
      that's true, it does get hot sometimes in Denmark where I am, but then I open the windows when that happens. My experience is it's either too cold to open the windows, or you will want the windows open - in my part of Denmark.
  - tallanvor 4y ago
    I don't think it was much of a problem historically, but anecdotally the summers have been getting worse* over the 15 years that I've been here. I finally had to break down and buy a portable air conditioner a few years ago. *Some people enjoy having more hot days during the summer, of course.
jnsaff2 4y ago
There are even products with 6 panes. Edit: one such product http://www.reflex.si/en/q-air http://www.reflex.si/en/q-air
doctorhandshake 4y ago
In the US the rating associated with this loss is called Visible Light Transmission, or VLT, and it can be quite low by percentage, especially in ‘Low-E’ windows designed for sunny climates. The nature of our perception of light intensity means that the use of a percentage of transmission might not be the best measure for the effect. I feel like something like the geometric scale of the f-numbers used in cameras would be more appropriate for how the change in light intensity feels, which I think is the intent of the VLT factor as there is also a Solar Heat Gain Coefficient (SHGC) that relates to the performance of the window in that regard.
- hgomersall 4y ago
  Low-e windows are not just for sunny climes - it's arguably the dominant benefit of modern windows. Interestingly, when you put low emissivity layers on each pane, it doesn't matter whether it's pointing towards the inside or the outside. When pointing outwards, it reduces the propensity to radiate outwards, when on the inside it reduces the propensity to be heated by radiation. More layers are good because that increases the number of low-e layers you have - with double glazing, you only have two on the insides; with triple glazing you have 4.
  - doctorhandshake 4y ago
    I don’t think you can generalize quite that much - on buildings in heating-dominated climates, low-e windows and their accompanying low SHGC result in rejected solar energy that could otherwise be used to heat the home by day. Without proper shading, overheating can be a concern in fall and spring for south and west facing windows but in my understanding north facing glazing shouldn’t be low-e in any heating dominated climate.

TIL quadruple glazing is a thing. Is the light noticeably more attenuated through 4 panes of glass compared to 2 or 3?

by ssl232 4y ago

TIL quadruple glazing is a thing. Is the light noticeably more attenuated through 4 panes of glass compared to 2 or 3?

bestham 4y ago

It is really hard to tell when every window is of the same dampening. But yes, I guess they lose some light.

bjarneh 4y ago

> Is the light noticeably more attenuated through 4 panes of glass compared to 2 or 3? I don't notice a difference now that I have two double glazed windows on top of each other (kobla vindu - I don't know the English word for it), I'll include a picture here: https://spesialvinduer.no/wp-content/uploads/2019/08/Skaara_koblet-vindu-8734-Edit-3-kopi.jpg https://spesialvinduer.no/wp-content/uploads/2019/08/Skaara_...

poooogles 4y ago
>kobla vindu - I don't know the English word for it) In the UK we'd call this secondary glazing if I'm understanding the image correctly.
- bjarneh 4y ago
  OK, an absolute nightmare to clean though. 4 surfaces on each window; and dirt/insects etc. can sneak into the space between the windows. But they look old cool and authentic I guess :-)

bradknowles 4y ago

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

empiricus 4y ago

It is a little worse than that: some triple glazed windows are intentionally made more opaque/green tint for 2 reasons: 1. easier on the eye when sunny outside, and 2. block up to half of solar radiation, to prevent overheating indoors

bryanrasmussen 4y ago
does Norway worry about overheating indoors though?
- ptman 4y ago
  I'm not in Norway, but here in Finland I don't appreciate having nearly 30C indoors in the summer.
- antipotoad 4y ago
  Not sure, but consider that summer months can have little to no nighttime owing to the northerly latitude.
  - bryanrasmussen 4y ago
    that's true, it does get hot sometimes in Denmark where I am, but then I open the windows when that happens. My experience is it's either too cold to open the windows, or you will want the windows open - in my part of Denmark.
- tallanvor 4y ago
  I don't think it was much of a problem historically, but anecdotally the summers have been getting worse* over the 15 years that I've been here. I finally had to break down and buy a portable air conditioner a few years ago. *Some people enjoy having more hot days during the summer, of course.

jnsaff2 4y ago

There are even products with 6 panes. Edit: one such product http://www.reflex.si/en/q-air http://www.reflex.si/en/q-air

doctorhandshake 4y ago

In the US the rating associated with this loss is called Visible Light Transmission, or VLT, and it can be quite low by percentage, especially in ‘Low-E’ windows designed for sunny climates. The nature of our perception of light intensity means that the use of a percentage of transmission might not be the best measure for the effect. I feel like something like the geometric scale of the f-numbers used in cameras would be more appropriate for how the change in light intensity feels, which I think is the intent of the VLT factor as there is also a Solar Heat Gain Coefficient (SHGC) that relates to the performance of the window in that regard.

hgomersall 4y ago
Low-e windows are not just for sunny climes - it's arguably the dominant benefit of modern windows. Interestingly, when you put low emissivity layers on each pane, it doesn't matter whether it's pointing towards the inside or the outside. When pointing outwards, it reduces the propensity to radiate outwards, when on the inside it reduces the propensity to be heated by radiation. More layers are good because that increases the number of low-e layers you have - with double glazing, you only have two on the insides; with triple glazing you have 4.
- doctorhandshake 4y ago
  I don’t think you can generalize quite that much - on buildings in heating-dominated climates, low-e windows and their accompanying low SHGC result in rejected solar energy that could otherwise be used to heat the home by day. Without proper shading, overheating can be a concern in fall and spring for south and west facing windows but in my understanding north facing glazing shouldn’t be low-e in any heating dominated climate.