Most of us desire big windows that fill our homes with an abundance of beautiful natural light. But the more sunlight you have streaming in, the more cash you will have going out to cover the heating bills, thatís if those windows arenít energy efficient, of course. There is a brand name of double-paned windows called "Thermopane" that comes with an airtight seal between the panes. Itís often used generically when addressing glass windows that reduce the transmission of heat through their panes.
If youíre thinking of purchasing new windows for your home, you should really consider energy efficient Thermopane windows. Make sure you look at the list of technologies employed when comparing different brands so you will get the best performance and value for your dollar.
One of the easiest ways to add an extra insulating ability to a window is to two panes of glass instead of one. The two panes will have an airspace between them, which will act as an insulating layer, lessening the transmission of heat through the window. All double-pane windows come with an R-value. Itís a measurement of its resistance to heat conduction. This value is about double that of a single pane window.
Triple-pane windows, come with three panes and two air spaces. This equals an R-value of about 3.1. Keep in mind that the extra weight of the glass may require you to enforce the frame prior to installing the window. Triple-pane windows are considerably more expensive when compared to double-pane windows because of the extra materials that go into its construction.
There are also insulating windows on the market that have the airspace filled with an inert gas such as krypton or argon. Since these gases are relatively dense, they donít conduct heat through the window as well as airspaces in a regular insulating window.
Another advantage of gas-filled windows is that they have fewer internal air currents that could cause cold and hot spots in regular windows because the inert gases donít move as easily. The R-value of a gas-filled window is about 30% higher when compared to a non-gas window.
Low-E (low-emission) coatings are thin metallic films added to the panes of insulating windows. They help to block solar radiation from passing through the window. This allows some solar energy to pass through from the outside while reflecting the interior heat back inside the house. Low-E windows commonly have an R-value of about 50% higher when compared to windows without the coating. So, a double-pane, gas-filled, low-E window has an R-value of 3.7. Whereas a triple-pane, gas-filled, low-E window has an R-value of 6.
Window panes in insulating windows are separated by spacers, which are usually made out of metal, a material which conducts heat well. Heat loss in windows is greater at the edges, so windows with metal spacers tend to be cold at the edges and warmer in the middle. This can create condensation and unnecessary heat loss through the window.
There are windows available with spacers made from a material with better insulating ability. They include plastic compounds or silicone foam. These materials aid in keeping the windowís temperature even across its entire surface area, making the window more energy efficient.