As to size and weight, the latest thin triple design is essentially the same width and weight of a double-glazed window— an improvement on the triple-glazed windows that are currently available because it avoids having to redesign the window sash and frame.
However, the advent of thin triple technology poses certain challenges for manufacturers and installers alike.
Manufacturing
Manufacturers will have to exercise extra care in glass cutting. Edge quality is critical because edge condition and strength affect the ability of the glass to cope with thermal stress. Because a chip as a percentage of glass thickness is much larger with thin glass, it can easily span the entire thick- ness of the lite. Extra care in handling and inspection is therefore indicated.
Producers of thin glazing are also challenged to limit deflection during processing and handling—whenever the glass is moved. Stiffer, better-supported cutting tables with more rollers to reduce unsupported spans and suction lifts with adjustable pressure are needed.
Also, post-fabrication quality-control inspection is not straightforward; once assembled, it can be nearly impossible to visually verify all product edge details. Quality-control efforts need to be focused on the center lite.
In addition, supply chain issues could interfere with thin triple production. For example, krypton pricing has been volatile for the last three years and it is currently quite expensive.
Installation
For installers, thin triples with their dimensions similar to those of double-glazed units, can offer the cost-saving advantage of “drop-in” installation versus having to reconfigure the entire opening.
Basic glazing guidelines are the same for triple glazing versus double glazing. Refer to IGMA TM-1300-13, Design Considerations for Multiple Cavity Insulating Glass Units, a document of the Fenestration and Glazing Industry Alliance (FGIA), for details. However, installers of thin triples should be extra careful regarding:
- Use and placement of setting blocks Blocks that are too small can focus weight on the center lite by pushing the spacer up into the glass.
- Handling Care in handling is especially important as larger size thin triple insulating glass units, increasingly preferred by architects, become more common. As noted, thin triples need better support.
Thin triple technology continues to be refined at a rapid pace with 0.5-millimeter-thick center panes now becoming available, as are seamless spacers that span all three lites instead of using two separate spacers on either side of the center lite. Aspects, such as safety glazing, high-altitude performance, and in-cavity blinds and grids are undergoing focused research and development efforts. As demand for advanced thin triples increases and inevitably spreads to the commercial sector, the industry will need to heed the modified demands that increased use of thin triples will impose on their production systems in terms of quality control, handling and installation.