Maybe there will be enough going on in SoWa to keep this thread alive? In any case, I didn't know where to stick this story.
Wind not a blow to South Waterfront buildings
Daily Journal of Commerce
by Alison Ryan
05/02/2007
The Willamette River isn’t Lake Michigan – and South Waterfront isn’t Chicago’s wind-whipping lakefront. But builders are still watching the wind factor as the growing district takes shape.
In some cities, watching the wind is a bigger part of building. The city of Toronto, for example, can require pedestrian-level wind studies for projects of more than six stories in some parts of the city. Studies evaluate pedestrian comfort during typical urban space activities – like sitting and walking – based on factors like wind force and wind chill.
But wind isn’t a factor in Portland’s review process for the South Waterfront District, Troy Doss, a city planner, said. An initial study of the North Macadam greenway microclimate, completed in 2000 by a University of Oregon team, showed that the way the wind blows through the district, as well as the way the streets are laid out, mostly shield South Waterfront from wind’s effects.
“The area tends to be more accommodating, in regard to the negative impact of wind,” Doss said. “But the proof will be in the pudding, when we see the district more built out.”
Wind isn’t often an issue in Portland. Monthly wind averages, collected since 1948, range between 6.5 and 9.9 miles per hour with an annual average of 7.9 miles per hour, according to 2005 National Climatic Data Center data. And according to Jan Curtis, a climatologist with the Natural Resources Conservation Service’s National Water and Climate Center in Portland, the city’s wind levels have been steady for at least the past 15 years.
Though architects and engineers consider wind effects, he said, studies would “generally not” make sense as a widespread requirement for Portland. The city is mostly established, he said, and heavy winds are fairly atypical in Portland and most U.S. cities.
“It’s generally something we kind of live with,” he said.
But it’s something that building teams are looking at anyway. As Oregon Health & Science University buildings, condominiums and other planned South Waterfront projects rise, the dynamic of the district will change. Both, developers say, in terms of urban life and in terms of how the wind moves through the area.
Planning the Center for Health & Healing, said Dennis Wilde, principal at Gerding Edlen Development Co., meant a computational fluid dynamics study – which involved computer modeling of wind – of the area by Arizona State University. Potential for wind turbines was explored, he said, as well as the dynamics created by the high-rise building. And the center, as the district’s first tall building, is experiencing some wind problems.
“It’s a huge issue for short periods of time,” he said. “But as other buildings go in and the neighborhood matures, those wind characteristics are going to change significantly.”
Designers for the Mirabella, a 30-story senior housing tower planned for South Waterfront, will study wind, a team from Ankrom Moisan Associated Architects told the Portland Design Commission on April 19.
Investigation into wind has also been a part of the process for project such as the John Ross Condominiums. The design team, TVA Architects principal Robert Thompson said, analyzed wind patterns as part of the John Ross design process – and the final design for the tower nods to the wind, too.
“The John Ross is an elliptical tower, so it’s far more aerodynamic than a rectangle or a square,” he said. “This allows the wind to pass smoothly by the building, creating very little turbulence as it goes by.”
Working on early South Waterfront projects means, Thompson said, that teams don’t have the luxury of factoring to-come projects into their work. But one thing the podium-tower design of some of the district’s first buildings, such as the Atwater and the Meriwether, do is create a street-level buffer that tower-only designs don’t have, he said.
Although the district’s wind dynamic will change as new projects wrap, South Waterfront’s well-positioned for wind. The street grid is oriented due north. Regulations focused on “permeability,” or keeping views of Mount Hood and the river within the district, bar facades wider than 125 feet on the north and south block sides, meaning buildings’ longer sides have to be oriented east and west. The district’s natural orientation doesn’t create wind tunnels, Doss said, but it does create a setup that’s good for harnessing solar energy.
“On balance, we’re in the black in the district more than anything else,” he said.
Gerding Edlen has seized solar’s potential, most notably through the photovoltaic system on the Center for Health & Healing. Designers left space, too, Wilde said, for wind turbines on the roof of the center, should technology for grabbing low-velocity wind appear on the market. But for now, he said, the same easy wind that makes the district a good place to build doesn’t offer a good return on turbine investment.
“We didn’t find consistent enough winds,” he said, “to justify the expense.”
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