BEC Special Session Closes Out Educational Program

by Charles Cumpston

LAS VEGAS-The Glass Association of North America (GANA) Building Envelope Contractors (BEC) Conference ended at the Monte Carlo Resort & Casino in Las Vegas on Tuesday afternoon.

Representatives from Lawrence Berkeley National Laboratory led the last part of the educational program, taking an in-depth look at the software programs and data bases for performing computer simulations for construction and product configurations.

Christian Kohler opened the program explaining the software available for analyzing energy data in simulations.

These include Optics (for the window glass), Therm (for the window frame), Window (for the whole window), Comfen (for the whole commercial building), and Resfen (for the whole residential building).

The programs are used for the design of new products and as guidelines for product selection and Energy Star compliance, he explained.

The programs use data from two data bases LBL has developed--IGDB (specular glass data source) and CGDB (complex glazing data base).

A new program is Window 6, which incorporates complex glazing systems, such as Venetian blinds, woven cloth shades and bug screens, and fritted/silkscreened glass. It has not been released yet, but a research version is available. Kohler said that they want people to go to the Web site and play with the program to see how it works and provide feedback. The program can be accessed at

Therm has been updated to conform with the shading systems in the new program, he said.

Currently NFRC is developing a procedure for laminates without embedded coatings, and interlayers that have originally been measured with clear glass. These calculated laminates will have the same 'status' as product submitted to the IGDB data base, Kohler told attendees.

Looking ahead, Kohler said that Window 7 will deal with dynamic windows with multiple and variable states, such as electrochromic glass.

Building Design Tools

Steve Selkowitz pointed out that these software programs are available for free, but he said that in the future there might be a charge for them.

He discussed how the materials allow façade performance to be optimized by examining daylighting versus cooling tradeoffs and energy versus comfort tradeoffs.

For those who had been attending the session over the previous day and a half, Selkowitz said, it should be clear how much more important daylighting is becoming to the architects and designers and thus to the glazing industry.

Selkowitz predicted that in a couple of years virtual lighting simulator software would be available and utilized in building design. He again discussed, as he had in his presentation the previous day, how such software has been used in pioneering efforts like the New York Times building, which is currently under construction in New York City.

The software, which has not been released yet, is available to experiment with at

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