The Wall of Wind
Why You Should Pay Attention
by Bruce Jasewic
Last month in this column I introduced the Wall of Wind, a storm-resistance research project spearheaded by Dr. Forrest Masters, assistant professor at Florida International University. I described the physical features of the Wall of Wind and what it can do. This month, I will explain why everyone in the building industry should take an interest in this important project.
The last two years have been brutal for the residents of the Southeast. Coastal residents took the brunt of severe storms while non-coastal residents endured large amounts of rain and wind. I saw homes that received no visible exterior damage from storms yet, in the interior, rain penetrated the paint, the stucco finish, eight-inch-thick cement block, insulation and sheet rock. Some of these homes were brand new, built to the latest codes, just waiting for the owners to move in. When a home leaks, people often consider their doors and windows the most likely culprits. We need to do everything we can to combat this tendency.
We all do the same water test. We take 15 percent of our design pressure and then use that number as a benchmark. Now take that same benchmark and try to explain to a customer how it is useful in designing doors or windows that do not leak. A customer asked me how it is possible to have a certified impact product installed in a 140 mph wind zone when the product was tested for water infiltration at only a 75 mph equivalent wind speed. I looked over my shoulder, expecting a TV consumer reporter to burst through the door, microphone in hand and camera rolling.
Masters and his Wall of Wind have a solution. Initially, we can use the data that Masters has collected with the Florida Coastal Monitoring Program (FCMP). FCMP places portable towers in the path of hurricanes before they make landfall. These towers measure and record actual storm conditions.
When Masters builds the full-size Wall of Wind, he will be able to use the data from FCMP to duplicate storm conditions on a full-size house. Not only will we be able to test doors and windows, but we will also be able to test all of the components of a house. Moreover, testing will be conducted using actual observed conditions. Design professionals will no longer need to rely on theories, computer simulations or wind tunnel models. We will have real data derived from realistic test conditions. Suppliers to the construction industry will benefit by being able to design and build to specifications that relate directly to the actual conditions that their products will encounter in use. The owner will benefit from being able to make a product choice based on testing that reflects real conditions.
Other organizations are trying to provide a realistic test method for water infiltration in doors and windows. The Japanese Industrial Standard JIS and the Australian/New Zealand AS/NZS 4284:1995 both attempt to simulate the wind gusts associated with storm-driven rain and their effects on water infiltration through doors and windows. An American Architectural Manufacturers Association task group is working on a new specification to simulate the same conditions. These are all good efforts, but the problem, again, is how to relate these tests to the actual conditions that a house will experience during a storm. If the standards to which we test are not relevant to the actual conditions, how can we promote our products’ performance during storm conditions?
The arguments against a more realistic water test have always been based on concerns of practicality. We’ve all heard arguments that a product designed to withstand the wind-driven rain of a hurricane would not be practical, would cost too much, would not be appealing and nobody would buy it. I remember the same arguments being raised when impact products were first proposed. Now impact products are the fastest-growing segment of our industry. I say let’s give our engineers the resources they need and see what they can design. y
Bruce Jasewic serves as director of engineering for WinDoor Inc. in Orlando, and is a member of the board of directors of the Fenestration Manufacturers Association.
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