A new type of window film can be used as a year-round energy efficient treatment to block the sun’s heat during summer and help block indoor heat from being lost in the winter.

The newer insulating window films use a technology similar to energy-efficient replacement windows. A low-emissivity heat barrier is deposited on the window film that reflects heat energy but allows most of the visible light wavelengths to pass through.

Another advantage of the newer window film is that it blocks most of the sun’s ultra-violet rays, which are responsible for much of the fading of carpet, drapes and furniture.

All window films block ultra-violet rays, but the low-emissivity coating is even more effective. Window films also help to hold broken glass in place, lessening the chance of injury and property damage. These films also make forced entry more difficult for would-be vandals and burglars.

If you have double-pane window glass, dark films might cause the window glass to get very warm. This can cause the airtight seal between the glass panes to fail. When this happens, a fog can form between the panes.

The almost clear low-emissivity energy-efficient films don’t cause the glass to get as hot because they block more of the sun’s heat instead of absorbing it.

Check with your window manufacturer about its warranty. Some makers void the glass warranty no matter what type of film you apply.

When shopping for do-it-yourself window film at a home-improvement center, the low-emissivity type often looks darker on the roll than installed. Do-it-yourself films are available in kits with a squeegee.

Installing window film on average size windows is easy. Make sure the glass surface is thoroughly clean and wet. A squeegee is used to force out bubbles so it adheres to the glass. If you want a long warranty on the film, have it professionally installed.

Federal Tax Credits
The Energy Policy Act of 2005 that allowed consumers to receive a federal tax credit for energy efficient improvements made on their home in 2006 and 2007 expired on December 31, 2007.

On February 27, 2008, the House passed $18.1 billion in renewable energy tax incentives (H.R. 5351), including an extension of the tax credit for energy-efficient home improvements. The bill is similar to the one passed last year, which was ultimately removed from the 2007 Energy Bill, signed into law in December 2007. This bill must still pass in the Senate, and be signed by the President to become law.