Green roofs typically do better when they don't bake in the hot sun. And solar photovoltaic panels boast more efficiencies at lower temperatures. So David Sailor, a professor of mechanical engineering at Portland State University, and his colleagues will experiment by pairing green roofs and solar panels to increase the performance of each.
It's the kind of project that's big on gritty details like soil depth and vegetation type and the distance between solar panel and plant. Picture researchers taking measurements and poring over lots of data. Again and again.
That's what Sailor does in his experiments, all of which aim to make buildings greener. And while he rarely has a eureka moment, he methodically questions and collects data and refines our understanding of existing technology so we use it better, and that leads to new developments.
It's not sexy, high-profile work, but it's important. So important the university and the Oregon Built Environment & Sustainable Technologies Center saw fit to fund a Green Building Research Laboratory at the university that Sailor will oversee. He hosted the open house just this week.
(The university funding came from the 10-year, $25-million challenge grant the James F. and Marion L. Miller Foundation gave the university in 2008 for sustainability, helping to make PSU a local gem when it comes to green research.)
Ultimately, Sailor hopes that industry in this region, which is ripe with green-building interest, will consider his lab a resource and partner on projects. And the lab will serve as a teaching tool for students.
And of course, Sailor will continue with his own fundamental research there. He built his career in part by studying the "urban heat island effect," which is how urban centers tend to be warmer than their unbuilt surroundings.
Sailor is focused on understanding how much heat people release into the outside environment from energy-consuming activities, say when they turn on air conditioners, which emit waste heat.
He also developed a modeling tool for the U.S. Department of Energy to answer efficiency questions like: What if I use three-inch versus six-inch soil on my vegetative roof?
The newer research going on inside the windowless Green Building Research Laboratory is varied and, at times, downright funky.
On one table, three-inch-thick squares of concrete with varying concentrations of "phase-change material" are hooked up to wire sensors. The phase-change material looks like salt, but each granule is a wax-filled polymer capsule. When the room warms, the wax inside the capsule melts, while the capsule remains solid inside the concrete. The researchers are testing how the concrete mediates temperature swings.
This is cutting-edge stuff a ways off from being part of everyday building materials, but eventually it might help save on air conditioning.
At the room's other end, a wind tunnel contains a model house. Researchers send streams of helium-filled bubbles and smoke over it to see how they move. This helps them understand a building's natural ventilation and how high, say, a wind turbine might need to be positioned on a building.
Then there's a spectrophotometer, which looks like a gigantic fax machine, that can assess the reflectivity of roofing materials. The more reflective the surface, the more solar radiation can be reflected away.
As Sailor sees it, Oregon is in great shape. Oregon State University has a lab focused on green building materials research, while the University of Oregon is working on architectural design to make good use of the sun.
And then there's his lab.
"Oregon has a huge opportunity to be a major player nationally in green building research," he said.
I believe it.
-- You can reach Carrie Sturrock at email@example.com
The Oregonian, September 18, 2009