Innovative Solar Window on Display at AIA
15 June, 2010

MIAMI (June 2010) – The Solar Window developed by Wendell Colson, VP R&D, Hunter Douglas will be on display at the Hunter Douglas Contract booth (#603). This demonstration product takes Hunter Douglas’ energy-saving efforts another step forward. Below, Colson explains the system and its architectural significance.

Q. Briefly explain the solar window on display at the AIA booth.
A. The Solar Window is a residential style, fixed glass window system, combining several new technologies that allow it to act as a supplemental heating device in cool weather. All windows lose energy, especially during the winter months. This revolutionary window, when used on an unshaded southern façade, provides a controllable and comfortable net positive heat gain.

Q. How can architects use this technology?
A. Most architects understand Passive Solar, the art of heating with the sun. They are also aware of the traditional pitfalls of overheating in shoulder months (spring/fall) and wide temperature swings. This window combines a series of solutions to these issues into a pre-engineered package that is easy to specify and install.

Q. What is the technology behind the Solar Window?
A. The thermal mass is the most important concept behind the Solar Window.  Since water is one of the best thermal storage materials available, our thermal mass is more than 90 percent water.  Plus a little magic.

Q. How does the thermal mass control heating and cooling?
A. Rather than having a thermal mass within the living space, the mass is within the window
glazing itself.  This allows more efficient collection of solar energy and more functional dispersion of that energy in the form of heat.  In addition, because the interior glass temperature remains warmer than room temperature for the majority of nighttime hours, there is little if any wintertime heat loss at the window.  This transforms the window into a
radiant heat source.

Q. What happens when there is enough heat, or in the summertime?
A. An important feature of the Solar Window is its motorized exterior louver system that
automatically controls thermal gain to the interior. The motorized louvers function as a solar thermostat. Solar heat delivery becomes superbly logical – it’s there when you want it, and not there when you don’t.

Q. The premise seems simple – let the sun heat the interior.  Why isn’t this a  common practice today?
A. Too many homes were built as Passive Solar in the 70s and 80s that did not incorporate
the proper control, storage, and insulation elements.  Temperature swings and overheating were a real problem.  We worked on many of those and came to an understanding of the combination of features required to remedy these shortcomings. We believe that by offering a pre-engineered combination of these features to the builder/architect, we can renew use of this very simple concept, and make a real difference in our energy needs.

Q. What would you like architects to take away from this presentation?
A. I would like to ask architects and builders to think of this not as a window, but as a
controllable energy device that also can bring in daylight and view.  When used in larger arrays over a substantial portion of the southern facing façade, it can comfortably and controllably contribute the lion’s share of winter heating. Because the heating function can be turned off, it adds less to the summertime cooling load than the wall it replaces.