All About Low-E Glass Windows
What are low-E windows? While you may have heard the term before, you might not know what it means what it applies to energy efficiency for your home.
Studies have indicated that about 705 of energy loss in the home escapes via doors and windows. And window glass accounts for 90% of the heat loss via windows. Low-E windows can reduce this number significantly, which results in monthly savings on energy bills.
Essentially, low E glass helps reduce the amount of ultraviolet and infrared light that passes through window glass without reducing the amount of sunlight. It is a transparent thin coating that is applied to the window when it is manufactured. Low E coatings reflect the indoor temperatures back outdoors to keep your home at a steady temperature no matter what the weather is outside.
The following factors are used to determine the level of effectiveness of low-E coatings for window replacement:
- U-value: determines to what extent your windows allows heat to pass through the glass.
- Light to Solar Gain: gauges the proportion between solar gain coefficient and VLT commonly known as visible light transmittance ratings (see below)
- Solar Heat Gain Coefficient (SHGC): factors the proportion of solar radiation that is absorbed or directly transmitted via the window glass.
- Visible Light Transmittance (VLT): measures the exact amount of visible light than is transmitted via the window pane.
Types of Coatings for Replacement Windows
Hard Coat Low E
Hard coating, or pyrolytic coating, is manufactured under high levels of heat by applying a layer of Low-E indium oxide. This then hardens into a transparent coating that reflects long wave heat energy from indoors and allows a minimal amount of infrared light to pass through the glass. Hard Coat Low E glass is recommended for those who reside in colder climates.
Soft Coat Low E
Ideal for those climates that experience both cold and hot weather, Soft-coated low E glass is designed to reflect both hot and cold air away from the window glass. The soft coating is applied to pre-cut window glass by an offline vacuum chamber while at room temperature and is sealed in a laminated or insulated glass unit before it is then installed in the window unit.
In addition to low-E coatings, you can also opt for double or triple pane windows that have been filled with inert gases between the panes for even more energy efficiency,
North Tech Windows and Doors provides Edmonton homeowners with the best selection of energy efficient windows in the area. Call us today for a free quote for Low-E glass windows.