Info-to-Build-On A Window on All Seasons by Raoul Hennin March 25, 2004 Windows provide light, but they also allow heat to radiate in all seasons.

Windows are a magical part of a home because they bring the outside in while separating us from the elements physically but not spiritually. What makes windows so special is their ability to transmit light, or, more broadly, electromagnetic energy. We actually only see a small segment of the energy that radiates through windows both into and out of the house. During the day, we experience radiant heat gain as sunlight pours in through the glass. At night the heat and light flow in the reverse direction as we turn on the lights and the temperature outside cools down.

With careful consideration and planning, the angle of the sun can play a helpful role in heating your home in winter and keeping it cool in summer. Because the summer sun is high in the sky, windows can be enjoy the shade of a small overhang in summer. During the winter months, the lower sun will shine in through these windows, below the overhang. We cover Solar Angle design in the Shelter Institute Climate class.

Even the most carefully conceived and executed window placement will fall victim to the awkward intermediate solar angles of fall and spring. These times of year, the outside temperatures are variable, a house can easily experience too much solar gain on a warm day - or not enough on a cool, cloudy day. During these seasonal changes, the windows that are so important to the character of a house can become a significant liability to heating, cooling and general comfort.

Solution. Window Quilt Shades are an elegant, energy efficient solution to most of the problems that windows experience: heat loss on cold days, heat gain on hot days, condensation, overly bright sunlight, loss of privacy during evening hours. While installing Window Quilts on every window in a house is an investment, and the installation process calls for attention to detail, this product works better than any other radiant barrier, shade product we have encountered.

Each year, my wife and I have purchased a few Window Quilt Shades and gradually outfitted just about every room in the house. These shades allow us to control the heat and light flowing into and out of the house through the windows at any time of day or night. While there is a long term cost benefit analysis, the real benefit is the daily comfort and useability of the rooms in our house throughout the year. Recently we have come to appreciate our Window Quilt shades even more because they help us to brighten or darken our children's rooms as needed - see photos below.

These shades effectively increase the R-value of your window from about R-1.5 to about R-5. But the R-value only tells a small part of the story because the radiant barrier inside the shade actually makes you feel more comfortable because radiant heat is sensible heat - we feel it. (Think about sitting at the table with bright sun pouring in on a hot day.) Another benefit from these shades is that they actually create an airtight seal around the window.

20% Sale through April 30, 2004. There is no better time to install Window Quilts than now in time for the solar angles of spring and the powerful summer heat. These shades come in a variety of styles and colors - call for pricing. Also, you can download the printable 4-page measuring instructions sheet in pdf format - it is a 3.2 MB file!

Window Quilt consists of a layered combination of quilting fabric, reflective mylar, and a quilting material which is mounted in a sealed track system on a roller with pull cord. For skylight applications, a balanced, spring-loaded roller allows easy adjustment. The weighted bar on the base of the shade ensures an airtight seal on the window sill while the sides are sealed by plastic tracks.