Hal Major © 2009
BobVila.com
Windows are the thermal black holes in your home. The average home can lose 30% of its heating and air conditioning energy through the windows. Energy efficient windows save money each month and year after year. The average payback period for installing energy saving windows is between two and ten years. However, with the latest round of
income tax credits for installing energy saving products the payback is substantially shortened. Here�s a rundown on the latest technologies in energy efficient windows.
Better Edge Spacers
You may be saying �What are edge spacers and what do they do?� The layers of glass or glazing in an energy efficient window have to be held apart at the proper distance to achieve the insulating effect. The original spacers were made from aluminum. Aluminum is nearly a super-conductor of heat and cold. The aluminum spacer produced an area of about 2.5 square inches around it that conducts the heat or cold. This effectively reduced the energy savings properties of the window.
The new and better edge spacers are made of non-conductive materials such as vinyl or insulating foam with a thin stainless steel shim for support. At zero degrees these new edge spacers improve the interior surface temperature from 4 to 6 degrees.
Tinted Glass
In warm climates the use of tinted glass to reduce the amount of sunlight that penetrates the home can keep inside temperatures down by four to seventeen degrees. The savings will be lower for homes located in areas that experience cool fall temperatures and cold winters. The warm sunlight is a welcome addition in these areas and tinted glass may block it.
Window Glazing
Energy-efficient glazing reduces water condensation in the winter. When low glass temperatures cause inside air to reach its dew point, water condenses on the window.
The new glazing materials for glass windows substantially reduce the chance of condensation forming on the inside pane because it stays warm.
Glass-Fill
The space between the panes of glass in energy saving windows gives another opportunity to improve the insulating properties of the window. The space is filled with an invisible and inert gas with low conductivity. The most common glass-fill agent is argon. There are however, other choices that work as well as argon.
Low E-Coating
The use of low e-coating literally changed the energy saving properties of windows overnight. A low e-coated window is a clear coating that is applied to the glass that allows the light in, but keeps the radiant heat out.
The coating comes in different grades for different climates and you wan to make sure you get the right one. You don�t want a low e-coating designed window for Seattle, Washington if you live in Miami, Florida. Always consult a reputable and experienced window contractor in your area for the right application and installation.
