Vinyl Windows Ratings: This Handy Guide Facilitates an Informed Choice

Vinyl windows are the most frequently installed type of new or replacement window in the U.S. Fortunately for homeowners, vinyl windows ratings are posted on every new window. The ratings tell you factors that are important in some climate but not others. Get the best energy efficient windows you can afford, but you needn't overspend.

How to Read Vinyl Windows Ratings

Become familiar with the components of the window label and write down the ratings appropriate for your area before shopping. Here's what to look for:

1. The map. The top of the vinyl windows rating label has a map. If a state or part of a state is shown in solid blue, the window is suitable for that area.
2. U-factor. This is how much heat flows through the entire window assembly. The lower the U-factor, the better the window resists heat transfer. Vinyl windows with gaps in the assembly will have a higher U-factor than a tightly-built window.
3. SHGC--Solar Heat Gain Coefficient. The SHGC is the ability of the window to block the sun's heat. The more heat a window blocks, the lower vinyl windows ratings will be for heat gain.
4. Visible Light Transmission. The greater the percentage of light that penetrates glass, the higher this rating will be.
5. Low-E glass. This glass has a transparent metallic coating that reflects heat back into the home in winter and reflects heat away from it in the summer.
6. ENERGY STAR rating. An independent organization tests and rates the energy efficiency of windows. ENERGY STAR windows qualify for a tax rebate through 2010.

The Department of Energy's website shows the best vinyl windows ratings by region. Fortunately lots of information is at your disposal for an informed choice. Vinyl windows may not be the right choice for all old houses, specifically when maintaining historical integrity of an old house, so be sure to look into all of your options when researching replacement windows.