Prior to this recent trend in hurricane wind zones, a typical insulating glass unit featured a sacrificial exterior lite with a laminated lite to the interior. After Wilma sent shattered glass raining into Miami’s streets, the Florida Building Code for the High Velocity Hurricane Zone was amended to require "safety glazing" for the outboard lite. As a result, many building owners began to move the laminated glass ply to the exterior. This often meant moving the Low-E coating to the #2 surface, the interior of the laminated ply. However, that affected the performance of the coating.

 

"Most Low-E and reflective coatings perform best when touching an air space," says Christine Shaffer, marketing manager at Viracon. "In hurricane zones and some international locations, customers are moving towards having a laminate outboard lite. For any project that cants outward 15 degrees or more, a laminate outboard is required. Our goal is to be able offer customers both energy performance and fallout protection, so we reviewed our processes to develop a way to provide the coating. the #4 surface."

 

With the help of new fabrication equipment, Viracon is now able to offer a variety of its coatings, including its popular, VE-2M Low-E coating on the fourth surface of the laminate. This offers improved U-values and solar performance to customers seeking an insulating unit with a laminate outboard.

 

In addition, placing the coating on the #4 surface allows for the use of a colored interlayer to the exterior without sacrificing performance. Previously, designers had to choose between placing the laminate to the exterior to provide vivid and vibrant colors or providing a high level of performance. Now, with the laminated outboard and a coating on the fourth surface they can have both striking color and high performance.

 

Source: GlassOnWeb