Insulating Glass Unit
Insulating Glass (a.k.a. IGU or ‘Insulating Glass Unit’) 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 Showers & More, Insulating Glass units are double sealed with a primary seal of poly-iso-butylene 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.
We offer multiple configurations of Insulating Glass units.
1” Clear IGU
+¼” (6mm) clear Annealed or Tempered Glass
+½” (12mm) airspace
+¼” (6mm) clear Annealed or Tempered Glass
The most common Insulating Glass Unit is constructed with two plies of glass and one sealed air space. This configuration is a dual pane or double pane Insulating Glass Unit, however is commonly shortened to ‘insulating glass.’
Insulating Glass is used due to the improvement in solar performance it provides. The most significant improvement is thermal performance (u-value) which improves by approximately 50% when compared to a monolithic glass ply. This improvement occurs whether the glass is coated or uncoated.
In addition to the improved solar performance, insulating glass offers a greater availability of coatings. Low-E coatings which cannot be exposed, and therefore cannot be used with monolithic glass, can be used inside the insulating unit where they are protected by the hermetically sealed space.
Insulating units also have more aesthetic possibilities than monolithic glass. The Low-E coating and silk-screen pattern, if desired, are applied to the exterior ply of glass leaving the interior ply available for additional treatment. For a spandrel location, a full coverage opaque ceramic frit can be applied to the inner face. For vision areas where daylight is desired but view through needs to be minimized, a translucent ceramic frit can be applied to the surface facing the airspace.
Insulating Laminated Glass provides the solar controlling properties of an insulating unit along with the safety features of the laminated inboard component. This allows the flexibility to design with hundreds of combinations of tinted glass, high-performance coatings, silk-screen patterns and pigmented interlayers, together or alone. In addition, Insulating Laminated Glass enhances acoustical performance, ultraviolet light protection, and the laminated component is designed to remain integral in the opening should glass damage occur. For this reason, insulating laminated glass is utilized for skylights or other overhead glazing applications.
Often the laminated inboard component is required to provide protection against man-made threats or natural disasters such as hurricanes, bomb blasts or forcible-entry. For information please see the interlayer component section.
A typical insulating laminated glass configuration is 1-5/16” thick overall constructed as seen on the attached image (above).
While insulating laminated glass provides numerous benefits from protection to safety to acoustic improvements, the solar performance between an insulating unit and the insulating laminated counterpart is nominal.
Laminated insulating glass is an insulating glass unit with a laminated outboard. This configuration can be used in applications where the exterior is overhead glazing or in specific hurricane zones where safety glazing is required for the exterior.
A typical laminated insulating glass configuration is 1-5/16” thick overall constructed as seen on the attached image on the left.
It is important to note, with laminated insulating glass there are two primary options for Low-E or Reflective coating placement within the unit. Coatings can be placed on the #2 surface, however superior solar performance can be achieved by placing the coating on the #4 surface, touching the air space.
Double laminated insulating glass units have both a laminated inboard and laminated outboard with a space in between. This configuration is often selected when improved OITC acoustic performance is desired such as in schools. In addition, double laminated insulating units can meet protective glazing requirements.
There are eight surfaces in a double laminated insulating glass unit and two primary options for Low-E or Reflective coating placement within the unit. Coatings placed on the #2 surface decrease solar heat gain; however, superior solar performance, including an improved u-value, is achieved by placing the coating on the #4 surface, touching the air space.
The most common triple insulating glass units are constructed with three plies of glass separated by two hermetically sealed and dehydrated spaces. This construction increases the insulating value of the glass unit, thus reducing the u-value. A triple insulating glass unit is especially useful in applications where a low u-value is necessary.
While it is possible to specify a 1” triple insulating unit to coincide with a 1” dual pane insulating unit, it is not always practical. A 1” triple insulating unit is constructed with 1/8” glass plies rather than 1/4” plies used in a 1” dual pane insulating unit. The reduced glass thickness increases the potential for distortion and since the 1/8” plies are not as strong as 1/4” plies, the width and height of the glass units must also be decreased. In addition, the solar performance improvement is minimal.
More commonly, triple insulating glass units are constructed with three plies of 1/4” glass and two 1/2” spaces. Our triple insulating glass units are available with the same Low-E coatings offered with dual pane insulating glass and the Low-E coating is placed on the #2 surface.
Please contact us with your measurement particulars regarding your IGUs so we can provide you with a detailed estimate.