Why is there no acrylic regular window?

[Decca]

After some research, it appears clearly that acrylic is better (cheaper, lighter, stronger, clearer, better insulation, better UV filtering) than glass. Only inconvenient: it expands and shrinks some with temperature variation. However, there are ways to deal with that as:
- there are boat ports (windows) made of acrylic
- there are storm windows made of acrylic
- there are window insulation panels made of acrylic
- there are block windows (real windows, but made of several little blocks of acrylic) made of acrylic.

So: why aren't regular, basic, primary windows available in acrylic? Anybody with a good answer to this one?

[Randy]

Just a guess here, but acrylic isn't very stable and therefore applying Low-E coatings to it would be a disaster.

[Windows on Washington]

+1

I think Low-e application would be challenging from the start in that case.

[TheWindowNerd]

It is soft(scratches), it cracks and crazes over a couple of years. It is not as stable/strong as glass in comparable thickness
It probably is not good for double pane sealing.

TheWindowNerd...

[Decca]

Thank you for your answers! I also looked very hard for answers elsewhere, and here are the conclusions:

1 - Low-e acrylic windows can't be found. I assume that Washington and Randy are right and it can't be applied. Just as a side note though, the energy efficiency and natural UV blocking of acrylic doesn't call for low-e. It naturally does better than a window with low-e.

2- it dulls and scratches easier than glass, that's true. However, there are some treated acrylic that is UV-stabilized and scratch resistant. I have such windows on my boat in Florida taking a beating everyday and looking great after 10 years. However, the lifespan is not unlimited like glass. After 10-15 years, it will look shitty.

3- Acrylic, although perfectly transparent, creates some kind of reflection depending on the angle it is viewed at. It might look "plasticy' especially on large surfaces.

These are the 3 downsides to acrylic. I still think that it would be very worth it having acrylic window for energy efficiency and strenght. With a lifespan of 15 years, that's no worse than most manufactured windows anyways (the glass will be fine but the frame will fail leading to window replacement anyways).
FYI I found several manufacturers ready to make acrylic windows, but the pricing was extravagant. I'll give up for now on acrylic exterior windows

[Oberon]

After some research, it appears clearly that acrylic is better (cheaper, lighter, stronger, clearer, better insulation, better UV filtering) than glass. Only inconvenient: it expands and shrinks some with temperature variation. However, there are ways to deal with that as:
- there are boat ports (windows) made of acrylic
- there are storm windows made of acrylic
- there are window insulation panels made of acrylic
- there are block windows (real windows, but made of several little blocks of acrylic) made of acrylic.

So: why aren't regular, basic, primary windows available in acrylic? Anybody with a good answer to this one?

It costs more (50-75%), it scratches much easier, and doesn't last nearly as long.

[Oberon]

Thank you for your answers! I also looked very hard for answers elsewhere, and here are the conclusions:

1 - Low-e acrylic windows can't be found. I assume that Washington and Randy are right and it can't be applied. Just as a side note though, the energy efficiency and natural UV blocking of acrylic doesn't call for low-e. It naturally does better than a window with low-e.

2- it dulls and scratches easier than glass, that's true. However, there are some treated acrylic that is UV-stabilized and scratch resistant. I have such windows on my boat in Florida taking a beating everyday and looking great after 10 years. However, the lifespan is not unlimited like glass. After 10-15 years, it will look shitty.

3- Acrylic, although perfectly transparent, creates some kind of reflection depending on the angle it is viewed at. It might look "plasticy' especially on large surfaces.

These are the 3 downsides to acrylic. I still think that it would be very worth it having acrylic window for energy efficiency and strenght. With a lifespan of 15 years, that's no worse than most manufactured windows anyways (the glass will be fine but the frame will fail leading to window replacement anyways).
FYI I found several manufacturers ready to make acrylic windows, but the pricing was extravagant. I'll give up for now on acrylic exterior windows

Although in direct comparison acrylic has slightly better conductive thermal performance than clear glass, glass with a LowE coating will outperform clear acrylic in overall energy performance.

Clear acrylic has a visible transmittance of 92%. Low iron glass has about 90-92% VT, and standard float glass has VT's in the high 80's, depending on manufacturer and float variations when dealing with glass.

Where in the world did you get the idea that "most manufactured windows" will have frame failure in 15 years?