The latest PPG insulating glass technology is the Intercept Warm-Edge Spacer System, which was commercialized in 1992. Recent estimates indicate that more than 50% of all residential windows manufactured in North America utilize the Intercept® spacer system.
Insulating Glass Systems
Features and Benefits
Intercept Insulating Glass Performance Comparisons
View Intercept Brochure
Insulating Glass Systems
Choosing the right window includes choosing the right insulating glass unit, which will determine most of a window’s energy performance. An insulating glass unit is comprised of two (or three) panes of glass and the insulating air space between them.
PPG’s Intercept system, with "warm-edge" spacers, features a unique, one-piece, tin-plated or stainless steel, U-channel design. This design creates an effective thermal barrier to help reduce conducted heat loss through the window and makes Intercept spacers stronger and better at retaining insulating gas than many conventional designs.
PPG has been an industry leader in the development and production of insulating glass since the late 1940s, when Twindow® Insulating Glass was introduced. PPG's commitment to ongoing research and development has provided the technical expertise required for the introduction of prior PPG insulating glass brands such as: Weatherpane® and Twindow products as well as our glass-edged Twindow XI insulating glass units.
Features and Benefits
1. Reduced Interior Condensation
Intercept® insulating glass units reduce condensation problems around the window perimeter. Compare the Intercept insulating glass window on the left with a conventional insulating glass window on the right. Both windows have low-e glass and argon infill. The difference is the Intercept "warm-edge" spacer.
 |
 |
| With Intercept® Spacer |
With Aluminum Spacer |
| Conditions: |
| Cold side temperature=0°F |
| Room side temperature=72°F |
| Room side relative humidity=25% |
2. Reduced Heat Loss
Intercept spacers are so energy efficient they keep the edges of the window glass warmer, so your home feels more comfortable in the winter. As you can see below, the temperature difference can be dramatic.
 |
 |
| Intercept Insulating Glass Unit |
Conventional Insulating Glass Unit |
This thermograph or “heat picture” compares room side glass temperature for an Intercept insulating glass unit (left: yellow is warmer; blue is cooler) and a conventional unit (right). Because the Intercept glass technology allows for significantly warmer glass temperature, especially at the edges, your home will feel more comfortable.
3. Improved Insulating Glass Unit Life
Less condensation means:
- Fewer stains or less damage to windows or walls.
- Higher allowable relative humidity indoors/less annoying static electricity.
- Better clarity of view.
Under normal weather conditions, insulating glass units expand and contract with temperature changes. In conventional insulating glass units, sealant takes the stress of the flexing, which can cause seal failure and insulating gas loss.
With Intercept glass technology, the spacers flex—instead of the sealant—to resist spacer movement and sealant failure.
With conventional aluminum spacers, the sealant must flex, which can lead to sealant failure and loss of insulation ability.
4. Warmer Glass Temperature
Warmer glass temperature means:
- Better insulating value (89% higher R-value).
- Lower energy bills.
- Fewer drafts, improved comfort.
Intercept® Insulating Glass Performance Comparisons
Compare the performance of windows using the Intercept insulating glass technology versus conventional insulating glass aluminum spacers. Intercept windows provide warmer indoor glass temperatures and lower U-values/higher insulation performance.
Window Unit Performance Comparison:
Intercept Insulating Glass Unit vs. Conventional Insulating Glass Unit
Window Unit Performance Comparison-Intercept® I.G. Unit vs. Conventional I.G. Unit
|
|
PPG Intercept® Steel
Plated Spacer |
Conventional Aluminum Spacer |
|
Center-of-Glass U-Value |
0.24 |
0.24 |
|
Emissivity (Solarban® 60* Solar Control Low-E glass) |
0.04 |
0.04 |
|
Edge U-Value |
0.34 |
0.45 |
|
Window U-Value (overall) |
0.28 |
0.31 |
|
Minimum Indoor Glass Temperature at Bottom Frame |
37°F |
32°F |
Conditions: 2.5mm glass thickness, 1/2" air space (argon gas fill), Solarban® 60 Solar Control Low-E glass, 0°F outside-15 mph wind, 70°F inside, 24" x 48" vinyl casement.
*Formerly Sungate 1000 Low-E Glass.
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