Low-e Glass Energy-efficient Windows

What are Low-e windows?

In low-e glass, E stands for emissivity. This glass was introduced in 1979. Low-e glass works by reflecting heat back to its source. It reflects heat back by using an ultra-thin metallic coating in the glass. This quality of the glass made manufacturers to use it for windows. A low-e glass window is a windowpane coated in microscopic layers of metallic oxides. The coating is invisible to the naked eye, and thus allowing natural light inside the house.

How does low-e window work?

Low-e coatings are microscopically thin, virtually invisible, metal or metallic oxide layers deposited on a window surface primarily to reduce the u-factor by suppressing heat flow. The principal mechanism of heat transfer in multilayer glazing is thermal radiation from a warm pane of glass to a cooler pane. Coating a glass surface with a low-e material blocks a significant amount of radiant heat transfer, thus lowering the total heat flow through the window. Low-e window has the ability to allow visible light while blocking certain amounts of UV and IR light. It keeps your house warmer in the winter by reflecting certain segments of the sun's light spectrum back into the home, and cooler in the summer by reflecting particular sections outside. These windows will create a comfortable living environment.

Types of low-e windows

There are two types of low-e glass windows.

Soft coat low-e windows: Soft coat Low-E glass, on the other hand, involves the application of silver, zinc or tin to glass in a vacuum. Soft coats are actually very strong in terms of their reflective capabilities, making them very energy efficient, however they can't hold up under extreme physical conditions so they have to be on the inside.

Hard coat low-e windows: Hard coat Low-E glass is manufactured by pouring a thin layer of molten tin onto a sheet of glass while the glass is still slightly molten. This process makes it difficult or hard to remove the tin. Hard coats are less efficient but can withstand the elements, and therefore are commonly layered on the outside surface of storm windows.

Benefits of Low-e windows

•  The low-e coating reflects heat back to its source so it helps your home stay cooler in the summer and warmer in the winter.
•  The low-e windows resist UV light from sun and hence it prevents the fading of draperies, sofas and other furniture.
•  Low-e glass reduces sunlight glare in a room
•  Low e glass allows sunlight into a room without letting heat inside. This helps to keep the room cool in summer.
•  Low-e windows reduce energy costs by helping to control the climate in the building.