Wildfires have ravaged the United States, with the National Interagency Fire Center estimating that 8.8 million acres have burned this year. The price of suppressing those wildfires has exceeded $2.2 billion, making it the costliest fire season on record, while the cost in human life has made it one of the deadliest.
The active wildfire season has prompted action on several fronts. U.S. Secretary of Agriculture Sonny Perdue and several members of Congress met on Sept. 26 to talk about the U.S. Forest Service budget, which "borrows" money from fire prevention to fund fire suppression efforts. It's a vicious circle: As more money is spent on fire suppression, less is available for fire prevention, which results in more fires. As fires increase in number and scope, so does the need for suppression, which costs more money.
On the environmental side, forest managers cite a need for proactive removal of small-diameter trees and woody debris, which serve as fuel for wildfires. The efforts are cost prohibitive, though, so the Forest Service has earmarked $7 million in 2018 grant awards for projects that expand wood products and wood energy markets in the hopes of developing new uses for the small logs and branches.
As legislators and ecologists grapple with solutions to wildfire prevention, help is coming from a unique source: the building industry. At the University of Arizona, one architect believes sustainable building practices can play an integral role in the future of wildfire prevention.
"I have a grounded interest in architecture that is more environmentally responsive and responsible," said Aletheia Ida, assistant professor in the UA's School of Architecture. "With our current building technologies, at any given time we're basically challenged in many ways to advance the performance of our buildings for environmental benefits. One of the things that I've been really interested in is: How can we think about enabling better forestry management?"
Ida's design research focuses on emerging environmental building technologies for regionally adaptive material and energy systems. Specifically, her interest is in the pinyon pine forests of the Southwestern U.S. Despite being a relatively drought-resistant tree, the pinyon pine has been affected by multiyear droughts, which have been extensively studied by UA professor David Breshears of the College of Agriculture and Life Sciences. Those droughts, coupled with high temperatures, have created pockets of dead and dying trees — perfect fuel for a wildfire.
"Fires in those forests have been increasing over time," Ida said. "Once there is a fire in that type of forest, it's basically wiped out. The concern from a forest ecology standpoint is that we can't recover that ecology. I'm coming from the position of: How can we prevent these fires from actually happening? Part of it is with specifically drought-ridden pinyon pine stock and working with material scientists to identify its properties — its ability to get wet and expand or dry and contract, and its thermal properties."
It seems counterintuitive to use wood as a building material, since wood is actually fuel for fire, but wood has been used to build structures for thousands of years. Wood treated with a fire-retardant material can actually reduce fire damage by creating a charred outer layer that prevents further burning.
"We will be trying to gain a fundamental understanding of the pinyon pine wood, and then determine how it can be processed," Ida said. "Can it be composited with other components like hydrogels? Once it's composited, could we create a dynamic hygrothermal building envelope?"
While her interest in the pinyon pine started when she joined the UA in 2014, Ida has been studying hydrogels since she was a doctoral student at Rensselaer Polytechnic Institute. She hopes to combine the two areas of research in a future National Science Foundation Faculty Early Career Development (CAREER) proposal.
In the meantime, she and Pierre Lucas, a professor in the UA Department of Materials Science and Engineering, are researching hydrogels with self-cooling and water recuperating properties for energy-efficient, building-integrated cooling systems thanks to an NSF Early-Concept Grant for Exploratory Research (EAGER) award. The technology may have the potential to reduce the reliance on energy and water for air conditioning and evaporative cooling systems.
"Right now, we're studying the fundamental properties of hydrogels for humidity absorption, and water condensation and release capacities," Ida said, adding that Derek Runge, a materials science and engineering doctoral student, is assisting with the research.
Theirs is not the first research to focus on hydrogels, which already has several commercial applications including thermal-regulating windows, shoe insoles and pharmaceuticals. Hydrogels also are embedded into the protective gear firemen wear, so it's not difficult to imagine they could also be utilized to increase fire resistance in buildings.
There are many questions that need to be answered first, however. Water, for example, is generally rejected in building applications due to its potential to create mold.
"Many years of research would need to go into it, but as a fundamental condition, having water essentially stored in a hermetic way within our exterior building skins is potentially a benign, safe and good way to protect extreme building damage from fire conditions, as well as improve building energy conservation," Ida said. "I believe there's a lot of potential to rethink how we compose our buildings, so the exterior skin materials would protect structures and interiors. If we begin to impregnate our exterior building materials with certain gels that would basically hydrate and self-cool, could we eliminate the possibility of the fire moving into the building? I think there's great potential."
The answers might be years away, but the research is a first step toward a potentially sustainable and economically viable solution to protecting buildings — and forests — from fires.