Low-E Window Glass: Pyrolytic Versus MSVD
Low-E glass is a new form of glass that contains special coatings which reduce the amount of both infrared and ultraviolet light that can pass through a window. By limiting such types of light, Low-E glass represents an incredible upgrade in terms of energy efficiency. If you would like to learn more about the different varieties of Low-E glass, read on. This article will discuss the difference between pyrolytic and MSVD production methods.
As noted above, Low-E glass contains a special coating. This coating is so thin as to be virtually microscopic, being roughly the width of a piece of human hair. Nonetheless, it is highly capable of reflecting infrared energy--in other words, heat. The easiest way to think of what Low-E glass does is by comparing it to a simple thermos. A thermos is able to maintain a constant interior by constantly reflecting its temperature back inside, while also preventing exterior conditions from penetrating in.
The first category of Low-E glass has what is known as a pyrolytic coating. Also known as passive Low-E coatings, pyrolytic coatings are applied to the glass while it is still in a semi-molten state. As the glass moves along its float line, the coating is sprayed into place, thus fusing with the glass. The resulting bond is highly durable.
Pyrolytic Low-E glass is especially prized for use in cold climates. That's because its nature allows a certain amount of short-wave energy--such as that produced by the sun's light--to pass through the glass. In other words, a building or home can still benefit from solar heat during the cold winter months, while still preventing interior heat from inside from escaping.
MSVD coatings are produced in a much different way. Here the coating is applied to glass that has already been manufactured and cut down to size. Also known as solar Low-E coatings, the MSVD coating is then sealed to the glass inside of a special laminating unit.
MSVD is much less permissive than pyrolytic coatings, in terms of both its emissivity and its control of solar radiation. In other words, unlike pyrolytic glass, glass treated with MSVD will reflect the sun's rays away from your home, not allowing them to enter through the windows. For this reason, MSVD is much more widely used in parts of the country with warmer climates, where air conditioning is the dominant HVAC appliance.
When considering new window installation, make sure you consider all of your energy efficient options.