Heat Reflective Window Films: A Low Cost Energy Efficient Alternative to Replacing Windows
Older windows are very poor insulators both because they do not have the dual pane advantage of trapping an air pocket between the panes, which enhances thermal performance, and because they are not low-emissivity, or low-e. Many homes still have these older single paned windows because replacing windows is a very large investment.
So what can you do to increase the energy efficiency of your windows without making the large investment of replacing all the windows in your home? Perhaps consider installing a heat reflecting window film, such as the one manufactured by 3M. 3M Heat Reflective Window Films are applied over a window, and they block out 99.99% of the sun's UV rays, and keep out 60% of the heat, thus keeping the house cooler, according to the company. And the company says you can get this performance for significantly under $100 a window.
The payback for using this product in residential properties is around 5 years, and the payback in a commercial property is usually around 2-3 years, according to the company. In addition, tax rebates are available that significantly reduce the cost of these installations and create a higher ROI in a much shorter time period. For example, 3M did a $650,000 film installation on the windows of an office building on Embarcadero in San Francisco, and this building is saving $320,000 a year in energy costs. After a $344,000 rebate from PG&E, it only took the property around a year to recoup their investment. In addition, since these window films help to save carpet and furniture from fading, you are also saving a great deal in furniture repair and replacement cost.
Check out the cool demo of the 3M window film in our video above, shot at this year's West Coast Green Conference. Interview given by Climate Insulating Products, a distributor of 3M Window Films.