Glass

High-Performance™ Low-E4® Glass

Andersen® Low-E4® glass, the next generation of premium glass technology, is standard on all Renewal by Andersen® windows and Frenchwood® patio doors.

Low Maintenance

Low-Emittance (Low-E) coatings on window glass can alter the flow of heat and light transmitted through the window. New Low-E4 glass features an innovative titanium dioxide (TiO²) exterior coating, which makes cleaning easier. When this coating is activated by sunlight, dirt loosens from the glass and can be washed away by rain. The special TiO² coating also makes the glass dry faster with up to 99% fewer water spots*. This coating also blocks 83% of UV rays that can fade fabric and damage furniture.

Energy Efficient

Our windows are up to 56% more energy-efficient in summer and 45% more efficient in winter compared to ordinary dual-pane glass.** Depending on where you live, that can cut your energy bills up to 25%***.

Without the Low-E coating, clear-glass windows can cause heat build-up inside your home in summer. And in winter, the warmth inside a room can radiate to the outside. You may not be able to see the difference in the glass we design, but we promise you'll feel it. This microscopically thin, metallic coating on the inner surface restricts the flow of radiant heat, helping keep your home warmer in winter and cooler in summer. It helps reduce ultraviolet and visible rays, while providing a clear, non-tinted view.

Our glass also uses a patented, low-conductivity spacer made of stainless steel that resists heat transfer much more effectively than the aluminum spacers used by many other manufacturers. An Argon gas blend is sealed between the glass to help inhibit the transfer of energy (heat or cold).

High-Performance™ Low-E4® SmartSun™ Glass

Our new High-Performance™ Low-E4® SmartSun™ glass is the most energy-efficient glass we have ever offered. It has our highest efficiency rating in cool weather and is exceptional in hot climates where solar heat gain is a problem. SmartSun™ glass blocks the sun's heat, while letting in almost as much natural daylight as clear glass, reducing your need for artificial lighting. What's more, SmartSun™ glass also blocks an amazing 95% of harmful UV rays.

Double Pane Windows Increase Insulation

Single-pane windows don't provide much insulation against cold or hot temperatures. Our double-pane (or double-glazed) windows have an airspace, typically one-half to one inch, sandwiched between two sheets of glass to provide an extra layer of insulation. If the space is too narrow, temperature is too easily conducted. If the space is too wide, convection currents are created that transfer heat or cold. In most double-pane windows, air trapped between the glass provides the insulation. In better double-panes, the space is filled with an inert argon gas blend. Argon has a thermal conductivity, or heat transfer rate, that is 30% lower than air, making it more efficient. They can also significantly reduces the level of sound coming into your home.

*On exterior surface when activated by sunlight.

**Values are based on comparison to U-Factors and SHGCs for clear glass non-metal frame default values from the 2006 International Energy Conservation Code (IECC).

***A study of identical homes comparing Low-E4® glass to ordinary dual-pane glass showed a 25% savings geographically on cooling bills, 10% on heating. Savings may vary geographically. Helps Keep UV Rays Outside High-Performance Low-E4 glass works like a sunblock to filter ultraviolet (UV) rays that can fade fabric and damage furniture. Ordinary dual-pane glass lets 63% of UV light pass through. High- Performance Low-E4 glass is layered with 11 microscopic coatings that cut UV transmission down to 17% with virtually no effect on the clarity or color of the light that enters your home.