Low Emissivity Glass

What is Sunlight?
‘Sunlight’ is radiation from the Sun.
Typically, the Solar Radiation that hits the surface of the Earth can be broken down into three parts:

Infrared
Infrared Radiation is effectively Thermal Radiation, as it allows for the transfer of heat. It is this component of Solar Radiation that allows us to feel the warmth of the Sun, and on a hot day, IR Radiation is responsible for turning a meeting room into a melting room.

Visible Light
‘Visible Light’ is so named, as it is the only component of Solar Radiation that we can see with the naked eye. Pretty obviously, we want to let this Visible Light into our homes and offices, otherwise we wouldn’t bother with a window in the first place.

Ultraviolet
UV Radiation cannot be felt, but is dangerous at a cellular and atomic level due to the destructively high energy that it possesses. UV Radiation is the component of solar radiation that is responsible for causing skin cancer, discolouring dyes and weakening synthetic materials.

The Problem
Unfortunately, a standard window will allow just as much IR Radiation and UV Radiation into your home, as it will Visible Light. These unwanted, and potentially harmful, forms of radiation traditionally come hand-in-hand with Visible Light, and for many years it was not possible to separate them.