The more layers of glass there are in a sash, the greater the thermal resistance of the window. Standard double-glazing has an insulation value of about R-2, as opposed to the value of a typical insulated exterior wall at around R-20. Modern windows are commonly double-glazed, and triple-glazed units are not unusual.
When the panes are installed, the space between the layers of glass should be filled with air, or an inert gas such as argon. Once the glazing is hermetically sealed, the gap actually provides much more of the overall thermal resistance than the glass itself.
Most seal failures in wood windows are caused by water entering the glazing pocket from the exterior in the form of rain, or from the interior as a result of condensation. Almost all window manufacturers** use foam tape, rubber glazing boots or other ineffective sealants in their glazing process to reduce labor costs.
After 30 years of experience, we know that these methods are not effective in a wet and windy west coast climate, and in this time we have developed a proprietary glazing process that makes the sash or door stronger, and eliminates water penetration from any source. While our method is time-consuming, we feel our customers' satisfaction is worth the extra expense. Adding extra layers of glass is the first step to increasing your home's energy efficiency. To cut energy costs further, consider using a coated or treated glass in your windows.
**Please note: Almost all window companies will supply a new sealed unit if it fails; however, the cost of the labor that is required to install the new window is deemed the responsibility of the owner (average installation costs range between four and ten times the price of the unit itself).
Super Sealed Insulating Glass
COATINGS AND GLAZING
A window's resistance to to heat loss is greatly augmented by the use of low-E [low-emissivity] treated glass. The virtually invisible coating reflects heat back into the home during the winter, and blocks out a portion of the radiant heat directed inwards during the summer. The use of low-E glass on a double-glazed unit can boost its insulation value to that of a triple-glazed window.
Low-E treatments are available in two basic types. One is more effective at keeping heat in the home, the other at keeping solar heat gain under control and reducing ultraviolet light from entering the home.
This type of glass is designed to prevent heat from escaping through a window's glass during the wintertime. These windowpanes are 'neutral' in colour, meaning that the tinting is nearly impossible to perceive. Low-E glazing is a nearly transparent treatment when viewing outwards. Reflected light on the exterior of the window may produce a slight tint or haze when looking in from the outside.
* Reduces winter heat loss through windows.
The term 'glazing' is applied to the fitted panes of glass in a windowframe.
LOW-E SQUARED GLAZING
This is a highly efficient glazing that serves the dual purpose of reducing energy loss in the winter and deflecting direct solar rays during the summer. Low-E squared glass significantly improves the thermal efficiency of a window in all seasons.
It allows for considerable visible light transmission, emits a low level of outer reflection, and has a neutral tint that still provides unfettered visibility.
* Efficient glazing that reduces winter heat loss and lessens heat gain from direct solar exposure. This is evident from the relatively low U-value (high R-value), and relatively low Shading Coefficient.
BRONZE TINT GLAZING
A bronze tint to the glass minimizes glare from the sun and the subtle tint provides aesthetic appeal. The treated glass reduces solar heat gain by roughly 25%, when compared with clear thermal glass.
Although bronze tinting is a warm weather application, it can be combined with a low-E coating to function efficiently year-round.
* Reduces glare and provides a tint for aesthetic appeal.
BRONZE REFLECTIVE GLAZING
The surface of this glazing is highly reflective, giving the glass a mirror-like appearance when viewed from the outside in the daylight. The same property produces reflection looking out at night when the interior lights are on.
It is designed to reduce solar transmissions by as much as 60%, and can be combined with low-E coatings for thermal efficiency in cold weather. This coating is most common in skylights, sunrooms, and other vertical or south-oriented windows with exteme sun exposure.
* Gives glass a mirror-like appearance when viewed from outside. After dark, with interior lights on, reflected images are seen from the inside.
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