Windows provide views of our outdoor surroundings, allow natural light to brighten our homes, and enhance the architecture of our homes. In addition to all these great benefits, windows can generally account for up to 30% of the annual energy consumed in a home. Considering the fact that glass makes up almost 80% of a window, and dictates how that window will perform, it's important to choose the right glass when replacing windows in your home.
Look for Low-Emissivity (Low-E) Glass, which is treated with thin, transparent coatings of metal oxide and silver. Low-E glass does the following:
(1) Allows natural light to freely enter your home.
(2) During winter months, long-wave heat energy radiating from indoor objects is reflected back into the house keeping your home warm while lowering heating costs.
(3) In the summer, outdoor long wave heat energy, radiating from objects is reflected back outside, lowering cooling costs. It also reduces the penetration of ultra-violet rays to minimize fading of carpet and draperies.
Also look for glass options that offer gas fills. Argon and Krypton are colorless gases that are denser than air. They increase the insulating value of the glass unit as well as providing insulation from outside noise. These gases are odorless, colorless, and non-toxic.
A major contributor to your primary window wintertime condensation, beyond excessive home humidity, can be its insulating glass spacer. Just as important as the glass itself is the spacer that seals the edges of the glass panes. Traditional metal spacers can conduct heat and cold, causing condensation at the edge of glass. Warm edge spacers keep the panes of glass separated without acting as a conductor to help fight heat loss and reduce condensation.
Furthermore, all-foam warm-edge spacers, typically available in advanced triple-glazed systems (see diagram at right), can offer additional insulating U-value and R-value benefits. Foam spacers inhibit heat escape paths at the glass edge, providing the best thermal performance. All-foam spacers also transmit very little sound compared to conventional metal spacers, keeping noise outside your home.
