Vinyl windows are the most frequently installed replacement window in the U.S. Fortunately for consumers, all vinyl replacement windows come with a rating label that helps a person determine how efficient a window can be.
How to Read/Interpret 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:
- U-factor. This is how much heat/cold transfers through the entire window frame (glass and vinyl). The lower the U-factor, the better the window resists heat/cold transfer. Vinyl windows with gaps in the framework (i.e. mechanical frames) will have a higher U-factor than a fusion welded window.
- 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.
- Visible Light Transmission. The more light that is allowed to flow through the glass, the higher this rating will be.
- 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.
- ENERGY STAR rating. An independent organization tests and rates the energy efficiency of windows. ENERGY STAR windows qualify for a tax rebate through 2013.