While windows, doors and skylights are one of the best ways to bring natural light and ventilation into a building, they are also the big weak spot in a building's thermal envelope. Given that most walls are typically built with an R-Value of 13, windows usually have an R-Value of only R3. That's a huge difference, and an issue that can't easily be overcome. Problem solving company, Serious Materials, recently came out with a new window that has an R-value of up to 11. Find out how they do it, after the jump.
Serious Windows are able to be so energy efficient because of a number of key design elements:
- Insulated Frames: The window frames and sashes are insulated with a high-density closed cell soy foam insulation which eliminates thermal bridging through the frame.
- Fiberglass Frame: Fiberglass expands and contracts at the same rate as the glass in the window, which further reduces energy leaks, unlike standard window frames made of wood, aluminum or vinyl.
- Suspended Coated Film: Rather than have two, three or four panes of glass, the windows utilize a suspended coated film which creates additional air pockets without putting weight on the sash.
- EcoSpacer: A high-strength warm edge spacer system, EcoSpacer
- Gas Filled Cavities: The air cavities are filled with krypton gases to slow the transfer of heat or cold air through the window.
- Low-E Coating: Low-E coated glass which reflects heat in and out of the home.
The windows come in four series, ranging from full-frame R-values of R5.9 - R11.1. All the series come standard with foam insulated frames and the EcoSpacer glass seal. The 525 & 725 series have a dual-chamber glass package (one layer of suspended film), while the 925 series has a triple-chamber and the 1125 series has a quadruple chamber. Lastly, all series come filled with Krypton (most energy efficient windows are filled with argon), and the 1125 series is filled with Xenon gas.
The 525 & 725 series is available in double hung, glider, casement, awning and fixed, while the 925 and 1125 series are only available in fixed, casement and awning &mdash this is because those three styles of operation provide the best seal when closed. The windows are available in a variety of prefinished colors as well as natural, stainable wood interiors. There is also a low cost vinyl replacement option, which starts out at an R-value of R3 and goes up to around R10.
And yes, the layers of suspended film do affect the clarity of the window, we've seen it in person, and the more layers there are, the more there is grayish tint to the window. Ideally, each side of the house would be treated differently and use more (or less) efficient windows where need to optimize efficiency and cost savings.
For more info visit SeriousWindows.com.
(Images via Serious Windows)