New and Developing Analysis Tools

In addition to understanding the forces of nature and how to control and channel them, architects in the United States face a challenge that architects in other countries do not: geographic diversity. With geographic and seasonal climates ranging from cold and dry to hot and humid, and mixtures of those, the rules of wall design change. While the architects of long ago calculated dew point—a measure of atmospheric moisture—with a calculator and pencil, computer capacity has allowed building scientists to create newer tools that take into account the entire expected atmospheric conditions of a geography for the entire year, and help match that with products and a system to achieve optimal desired performance.

Karagiozis helped design the sophisticated WUFI (the name stands for Wärme und Feuchte Instationär, or “Transient Heat and Moisture Transport”) software, which he says is now an industry standard that takes the guessing out of whole-building material and system specification. According to the Oak Ridge National Laboratory, where Karagiozis helped introduce the software and trains architects to use it, WUFI “is a menu-driven PC program which allows realistic calculation of the transient coupled one-dimensional heat and moisture transport in multilayer building components exposed to natural weather. It is based on the newest findings regarding vapor diffusion and liquid transport in building materials and has been validated by detailed comparison with measurements obtained in the laboratory and on outdoor testing fields.”

Further, software can now help architects design wall systems for desired service life. For instance, an architect designing a one-story strip mall that will be refurbished every 10 or 15 years does not need to specify a 500-year wall.

“He or she does not need to invest valuable resources for that period of time,” Karagiozis says. Rather, the architect can now, aided by software, design the building for the anticipated service life, whether it is 15 years for a strip mall or indeed 500 years for an art museum.

“I think this is the power era we are entering,” he says. “This is the era of breakthroughs that we are in today.”

Looking to the Future: A Systems Approach

To review the basic concepts:

• The forces of nature work on a building and must be controlled.
• Liquid control is on the outside, not the inside of a wall system.
• Thermal control’s optimum is outside to shut down thermal bridging, but architects can also take advantage of valuable space by insulating inside the stud cavity.

With thousands of materials on the market, compatibility and complete system performance are becoming ever-increasing concerns. Some building product manufacturers have teamed up with other manufacturers and compiled and tested complete systems for various applications, climates, performance, and anticipated service life. The architect would be well-served to take advantage of those complete, tested assemblies when specifying walls systems.
 
But the savvy architect will strive to understand building science: the forces of nature, and the building materials and systems that control those forces.

“I really think architects need to own this space as they own this space in other countries,” says Karagiozis, the building systems expert.

“Architects,” he believes, “are society’s heroes of the future.”