A remarkable new glazing system has been available in Europe for several years and is now being brought to the North American market. The GlassX window is an insulated glass assembly that incorporates a phase-change material (PCM) between two of the glass panes in the window. At lower temperatures, the PCM is a translucent solid. But, as it heats, the PCM melts and becomes transparent. This lets the window itself absorb heat from solar energy during the day, and then releases the energy again later on, as the material cools again.
The combination of good insulating windows along with heat storage makes these windows very useful for passively designed buildings. PCMs are excellent heat storage materials, and the GlassX windows are able to store as much heat as a 9" thick concrete wall. Even in its solid, translucent state, the GlassX windows allow more than 25% of the exterior light through, so that daylighting is not entirely lost. The windows also incorporate a diffuser that reflects high angle light from the sun in summertime, while allowing low angle light in the winter to pass through more directly.
These are not ready replacements for the current windows in most homes. The GlassX windows are over 3 inches (8 cm) thick and weigh nearly 20 pounds per square foot (100 kg/m2). They are also rather expensive at $60-90 per square foot ($560-$970/m2), but the company expects payback on these to be under ten years. There are several installations of the material in Europe, but as yet there are none in North America.
via: @bglive
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written by Shefali, June 22, 2010
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written by Jacob, June 23, 2010
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written by Marc, June 23, 2010
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written by Tom Donaldson, June 23, 2010
Early adopters will ignore the payback period. But for most folks, the payback period should be significantly less than the length of time they will own the home. So, for the average home owner in the USA, payback should be three years or less.
Of course that ignores the fact that the windows will increase the value of the house somewhat. But "higher house value" is not as easy a sell as "payback in three years".
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written by John, June 24, 2010
There's some really interesting things going on in environmental design right now. I found this awesome blog that talks about a web series that will highlight eco-design in different environments: http://workbookproject.com/labs/blog/
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written by Foraker, June 25, 2010
The same window that might work well in Munich could be a disaster in Miami or Maine. Or it could work great in the winter, but create more problems in the summer. What if in Florida the material absorbs all the heat it can take before 10am, and then it passes heat into the home until 3am. Talk about working your air conditioner overtime!
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