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What is LoE3 glass and why is it standard on VELUX skylights?

It's part of what makes VELUX skylights energy efficient.

Two skylights with gray blinds over a built-in shelf

There was a time when having skylights meant your home experienced excessive heat in the warmer months accompanied by an unwelcome greenhouse effect. Well, those days are gone.

VELUX Skylights come standard with energy efficient LoE3-366® glass, which is far superior to the acrylic skylights of yesteryear. Energy efficiency and durability aside, glass skylights do not change color over time, reduce external noise and—when installed properly—won’t leak or allow drafts.

Every VELUX skylight has LoE3 and Argon gas injected into its dual glass panes. LoE3, or low-emission cubed, is a virtually invisible metallic oxide layer placed on the surface of the skylight to reduce its U-factor by subduing radiative heat flow through the skylight. Even on cloudy days, 80 percent of UV radiation makes its way past the cloud cover. By reducing the amount of ultraviolet light and radiation, LoE3 protects your family from potentially harmful rays of sun, and your furniture from damage and fading. Argon is a colorless, odorless gas that is often used in electric lamps and fluorescent tubes. Since it’s denser than air, it provides better insulation. When sealed between two panes of glass, it allows less heat to seep through during the summer and less cold air to enter your home in the winter.

For ultimate performance, we’ve taken it a step further with LoE3-366® glass to offer the perfect balance between solar control and uninterrupted visibility. 366 simply means there are three layers of the coatings with 66 percent light transmittance for the glass only. It’s the only glass that guarantees compliance in all four ENERGY STAR climate zones for a double-pane window.

By blocking 95 percent of the sun’s damaging ultraviolet rays, your furniture, carpets, curtains and wall coverings are safe from fading. Additionally, the superior insulating capacity of LoE3-366® glass keeps interior temperatures moderate and comfortable during cold weather.

Neat® glass—which features a smooth surface that disperses water quickly and evenly to expedite dirt removal and lessen water spots—is applied to LoE3-366® glass to offer the ultimate solution for low maintenance skylights with energy savings of up to 25 percent annually.

Next: What is skylight flashing?

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