Insulating glass is two or more plies of glass enclosing a hermetically sealed air space. Inherently, insulating glass increases a window's thermal performance by reducing the heat gain or loss.
At Viracon, insulating glass units are double sealed with a primary seal of polyisobutylene and a secondary seal of silicone. To provide a hermetically sealed and dehydrated space, the glass plies are separated by a desiccant-filled spacer with three bent corners and one keyed-soldered corner or four bent corners and one straight butyl injected zinc plated steel straight key joint. The desiccant absorbs the insulating glass unit's internal moisture.Components
When specifying insulating glass, it is important to select and clearly outline the configuration as well as each individual component of the insulating glass unit.
• Appearance: Color choices include a black painted finish or a mill finish which has a silver appearance. The color of the spacer does not affect the solar performance of the insulating glass.
• Thickness: The thickness determines the distance, or space, between the two glass plies in an insulating unit. Viracon’s typical 1” insulating units are constructed using a 1/2” (13.2 mm) nominal thickness spacer.
• Material: Aluminum, Stainless Steel and ExtremEdge™ are the three spacer material options available from Viracon.
Glass substrates are the individual plies of glass used to fabricate glass units and may also be referred to as float glass, raw glass or glass lites. Glass substrate options include clear, tinted and low iron.
Glass Heat Treatment
Heat-treated glass is a term used to describe glass that has been processed through a tempering furnace to alter its strength characteristics. The process is done in order to provide greater resistance to thermal and mechanical stresses than annealed glass. There are two kinds of heat-treated glass, heat-strengthened (HS) and fully tempered (FT).
Coatings are thin layers of metal applied to glass to improve solar performance. The most popular coatings applied to glass are low-emissivity (Low-E) coatings. They have low heat transfer properties and offer higher light transmission than reflective coatings. Viracon’s coatings can be applied to clear or tinted glass substrates.
Viracon offers a choice of black or gray silicone for insulating glass. When black is specified, both the PIB and silicone will be black as is the case when gray is specified.