High Performing Low-Emissivity Glass (LoE glass)

As the name suggests, Low-Emissivity Glass (LoE glass) is a kind of window glass that gives off low emissivity. Emissivity is the ability of a material to radiate and transmit heat and while some absorb heat, others reflect away the heat.

Coatings are an important factor in the energy performance of your windows and doors. They

either filter long wavelengths (heat) and allow short wavelengths to pass through or vice versa. Light-coloured surfaces like aluminium foil have a very low emissivity, while dark-coloured surfaces like asphalt have high emissivity and will get hot.

How LoE Works?

These coatings are extremely thin layers applied to glass to increase the energy efficiency of your windows by reducing the emissivity of one or more of the glass surfaces.

In winter, internal long-wave heat energy reflects back inside, keeping your home warm and lowering heating costs. Meanwhile, in the summer, long-wave heat energy radiating from the sun is reflected back outside, helping to keep the interior of your home cool so every room in your home stays comfortably cool all summer long.

The purpose of the Low-E coating is to reduce the amount of solar radiation or heat transference into a building from the infrared portion of the sun while still allowing a high degree of light to come into the building. In summary, the purpose is to provide a low Solar Heat Gain Coefficient (SHGC), a low fading transmission value and a low air leaking rating (AL).

Low-E glass is used to minimize the amount of infrared and ultraviolet light that penetrates the glass, without minimizing the amount of light that enters your home and damaging your home’s interior furnishings.

Types of LoE Coatings

Solar Control Low-E Coatings (Soft-Coat): Soft coating is produced using the Magnetron Sputtering Vapor Deposition (MSVD) process and is applied off-line to pre-cut glass to the glass in multiple layers in a vacuum chamber after it has gone through the float line process and has cooled down.

It is enclosed within a double-glazed unit or an insulated glass (IG) for superior solar control performance, longevity and a nearly invisible coating. The soft coat offers optimum winter u-factors, and up to 70% less UV transmission compared with standard clear glazing.

Hard Coat LoE or Pyrolitic coating: A hard-coat Low E glass is a kind of glass coating that is sprayed on the glass surface at a high temperature, usually when it is just coming out of the furnace so it is fused to the glass as it cools down. The hard coat LoE has a higher SHGC (Solar Heat Gain Coefficient for passive heating applications, is durable and can be tempered for increased safety.

Hard Coat LoE is designed with the purpose of maximizing solar heat that passes into a building and is ideal for the Canadian climate as they can significantly reduce the cost of heating in your home.