John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
This is the only fan in America that can recreate the terrible conditions of a Category 5 hurricane.
Hurricane Andrew, in August 1992, brought Floridians abruptly up to date on the sorry state of their building codes. The Category 5 cyclone ripped roofs off with ease and smashed down doors with airborne debris. When the storm finally moved on to Louisiana, more than 125,000 homes in the state lay in waste, victims to a crushing natural disaster that at the time was the costliest (around $27 billion) in history.
Florida's done a lot since 1992 to make sure its buildings are better protected against fierce storms. Hurricane straps are used over clips, doors open outwards and masonry components are glued together with concrete. But when we're talking about a fusillade of sustained winds above 155 m.p.h., the definition of a Cat. 5, no amount of caution is enough. That's why on the eve of Andrew's 20th anniversary, researchers in Miami have rolled out an $8 million hurricane-simulation machine known as the "Wall of Wind."
Actually, the WOW (that's really what they call it) has been in the making for five years, as you can see from this old video of "destructive roof testing." But its tenders at the International Hurricane Research Center, part of Florida International University, have jacked it up with even more gigantic fans. Now the array holds a dozen 6-foot-tall, 700 horsepower, ungodly noisy fans, giving it the ability to generate winds as fast as 157 m.p.h. That's a little behind Andrew's peak land gust of 165 m.p.h. But still, in America, no other fan array can blow so hard.
The researchers debuted the new-and-improved WOW yesterday in a test run that put a simulated pre-Andrew house next to a modern-day home. As you can see from this recording of the experiment, the state was correct to revamp its building codes after the '90s megastorm:
Shown here is the classic way that hurricanes scalp houses. The wind rushes over the peak of the roof so hard that it's creating a vacuum below it, which helps lift the top of the home into the air. It is WOW tests like these that are helping Florida continue to fine-tune its building regulations, according to university officials. They write:
The Wall of Wind research team, under [Arindam] Chowdhury’s direction, has already had a significant impact in mitigating hurricane damage by enhancing building codes, validating innovative mitigation technologies, and developing new materials. In fact, the team has a patent pending for a new type of roofing material. Recommendations made as a result of Wall of Wind testing were published in the 2010 Florida Building Code. The new code provisions are geared toward decreasing the vulnerability of roofs and rooftop equipment.
All in all, this is some very cool and timely technology, what with climate change expected to spawn ever-more-intense hurricanes. Although if anybody from the WOW team is reading, next time you run a test like this could you please include Jeff Morrow live on the spot?