Window Coverings address one of the main culprits in energy inefficiencies – those holes in the wall filled with glass. Yes our windows allow the cold air to seep in in winter and for the sun to penetrate in summer. So to answer the question: What is a Green Window, it is a window in a residential, commercial or institutional facility that is treated by a window covering to prevent the loss of heat in winter and to filter out solar heat gain in summer months with sustainable products and ideas.
Keeping the Heat Out
The best way to filter out Solar Heat gain on eastern and western exposures in the summer months as well as southern exposures in winter months when the sun in low sky, is with Solar Roller Shades.
Solar Shades have two main characteristics in deciding upon the appropriate fabric which are the density of the weave and the color of the fabric. The density of the weave is also referred to as the openness factor. The weaves are available in 1, 3, 5 and 10% openness. This means that is a 3% weave, 97% of the shade material is closed. In deciding upon the percentage of the weave there are the considerations of the exposure and the desire for a view. 1% is the tightest weave and provides the most sun protection but allows very limited view through the fabric. This is a good choice for a bathroom application where privacy with light filtration is important. 3% and 5% are the best options for windows getting direct sun, while 10% is typically suited for northern exposures.
Color is also critical. Light colored fabrics provide more heat reduction while dark colored fabrics perform better for glare reduction. Also, the darker colored fabrics allow for better see-through visibility then the lighter colors.
Keeping the Heat In
The measure of a products ability to resist heat flow is called R-Value. The higher the R-Value the better the performance of keeping the heat from escaping through the windows. Any treatment that can trap air offers the better options and higher R-Value. For example cellular shades with its honeycomb design offers very high R-Values and when you add side tracks these numbers climb.
Drapery as an Insulator
Just like with cellular shades, a drapery treatment can trap air and act as an insulator when it is double lined. In fact, a double lined drapery has 310% better energy efficiency then an unlined drapery.