Your building melts cars? There's an app for that

An epidemic of curved glass buildings is endangering people with heat and glare. Yet a simple analysis could solve the problem during the design phase.
Written by C.C. Sullivan, Columnist (Architecture)

Whatever shred of respect I had for Rafael Viñoly, a celebrated architect who turns 70 next year, that shred disintegrated last week.

It was not that Mr. Viñoly's 20 Fenchurch, the so-called Walkie-Talkie skyscraper in London, was concentrating the sun's rays in a manner powerful enough to melt a car's rear-view mirror. Nor was it because Viñoly also designed the Vdara Hotel and Spa in Las Vegas, a vulgar MGM Aria property that opened in 2010 to news that it trained solar reflections in an unsafe and uncomfortable way, reportedly burning guests on its pool deck. 

No. What disappoints is Viñoly's blithe manner and willful ignorance in the face of these discoveries. It gives architects a bad name, and perpetuates the myth that architects are nothing more than licensed artists, motivated by the grand gesture and indifferent to watertight roofs.

Not my fault

Viñoly told the Guardian -- disingenuously and perhaps jokingly -- that the problem was too many consultants. Or global warming, which suddenly made London very sunny. Or, bizarrely, "the current elevation of the sun in the sky." As if that's also a surprise.

Then he added, "I knew this was going to happen. But there was a lack of tools or software that could be used to analyze the problem accurately."

Now that's just a damned lie. Ask Vicente Montes-Amoros of Curtainwall Design Consulting, Inc. (CDC) The company is based in Dallas, not far from where Museum Tower is reflecting art-damaging sunlight onto Renzo Piano's lovely Nasher Sculpture Center.

Montes-Amoros and his firm have the killer app for death-ray buildings. It's inexpensive, it's accurate and it has been used around the world.

Solar convergence

CDC's software suite and modeling techniques are known collectively as solar reflectivity analysis. It's a highly accurate tool using computational fluid dynamics (CFD) to show where the sun's rays are concentrated at any time of day, any time of year. Architects and their clients like to run the algorithm a dozen times or so to analyze conditions throughout the year for a proposed building.

CDC isn't the only option. There are similar if less sophisticated tools on the market also.

Viñoly should study up on these products. A couple of miles from his New York studio, there's a big model of Lotte World Tower, designed by the venerable architects Kohn Pedersen Fox, which has been tested and tweaked based on CDC solar reflectivity analysis.

It's no secret either. Montes-Amoros presented CDC's work on the 123-story Lotte skyscraper at the BEST3 conference in Atlanta in early April 2012. (Yes, I was there. Yes, it was cool.) The paper presented last year is free to download, right here, courtesy of the National Institute of Building Sciences and the brilliant archi-geeks at the Building Enclosure Councils.

In our era of building information modeling (BIM), it's easier than ever to use predictive modeling to make architecture better, safer and more energy efficient.

No gray area

"Until now, knowing exactly how the sun will reflect off a building has been, at best, gray," Montes-Amoros told us, running through three-dimensional pictorial simulations showing paths of the solar reflections, glare intensities, and even shadows thrown by Lotte's 1,800-foot-tall, convex glass façades. "Now we can help predict and quantify how buildings react to the sun, and the effects and intensity on the surrounding areas."

In fact, the effects of nuisance glare on motorists and adjacent buildings has long been studied to avoid lawsuits and civil fines. But instead of hiring an astronomer, architects like Viñoly need only engage a good team like CDC to get straight answers for their curving glass curtain walls.

It's a small investment that can save a lot of cost down the road. Montes-Amoros says the fix for the Vdara hotel's "solar convergence" problem is by no means minor. All that's needed is to rotate the building 180 degrees, he joked, or just pick it up and move it to another site.

For the 20 Fenchurch project, a number of costly retrofit corrective measures have been floated. And the project's owners will likely have to fork over a pile of cash to add exterior louvers, window film, or hopper-style windows that can be angled when the fog lifts. At the Vdara in Las Vegas, MGM tried a window film, but to no avail. It failed to correct the solar heating issue, something many architects anticipated.

In fact, the original design for 20 Fenchurch included horizontal louvers to control solar heat gain -- and, presumably, to control reflectivity -- but they were removed as a cost-cutting measure.

Cheap fix

Not a smart move. But even these kinds of "value engineering" changes can be quickly reviewed and tested against the computer model, Montes says.

Should he be awarded any, for his next commissions Viñoly can easily add solar reflectivity analysis as a pass-through cost in schematic design or design development. He owes it to his clients like MGM -- and the REIT Land Securities Group and Canary Wharf Group, which gave the green light to the hulking, ungainly Walkie Talkie. Owners and developers will appreciate it as a way to boost their fiduciary responsibility to stakeholders.

Architects owe it to the public as well. Their work must first do no harm, and in fact must protect the public health, safety and welfare.

Land Securities and Canary Wharf issued a statement to Business Insider that echoed Viñoly's comments, blaming the mere existence of the sun for their sticky wicket. "The phenomenon is caused by the current elevation of the sun in the sky," they stated. "It currently lasts for approximately two hours per day, with initial modeling suggesting that it will be present for approximately two to three weeks."

To solve this problem, perhaps the developers would rather move heaven and earth?

This post was originally published on Smartplanet.com

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