Energy Star Information and Guidance

The information found on this section of our web site has been derived from the www.energystar.gov web site.  For additional information on energy saving recommendations, please visit the site.

What makes a window energy efficient?

Improved Frame Materials
Wood composites, vinyl, and fiberglass frames reduce heat transfer and help insulate better.

Low-E Glass
Special coatings reflect infrared light, keeping heat inside in winter and outside in summer.  They also reflect damaging ultraviolet light, which helps protect interior furnishings from fading.

Multiple Panels
Two panes of glass, with an air or gas-filled space in the middle, insulate much better than a single pane of glass.  

Gas Fills
Some energy-efficient windows have argon, krypton, or other gases between the panes.  These odorless, colorless, non-toxic gases insulate better than regular air.

Warm Edge Spacers
A spacer keeps the window’s glass panes the correct distance apart.  Today’s warm edge spacers – made of steel, foam, fiberglass, or vinyl – reduce heat flow and prevent condensation.

Projected Energy Cost Savings
According to a study performed by Lawrence Berkeley National Laboratory, as published at http://www.energystar.gov/ia/products/windows_doors/CitySavingsEstimates.pdf, for the average home in the Atlanta area with single paned windows, installing EnergyStar qualified vinyl replacement windows will result in an average of energy cost savings of $465 per year.