Both Landscape and Architecture
Both Landscape and Architecture Section through double-wall systems that use Breathe Brick to supply air directly to a building interior (left) or to an HVAC unit (right).

In Cairo, an annual temperature inversion brings a fog of dust and burning biomass called the Black Cloud. When Carmen Trudell began researching the city’s air quality problems five years ago, she thought about her brother’s treatment for kidney failure: What if a building, like the organ, could filter toxins and protect people?

Since then, Trudell, now at the firm Both Landscape and Architecture, in Charlottesville, Va., and an assistant professor of architecture at California Polytechnic State University, San Luis Obispo (Cal Poly), worked with students and fellow environmental engineering associate professor Tracy Thatcher to develop a building component that could double as a passive filtration system. The product would be easy to construct and work without electricity to allow its use in developing countries.

Both Landscape and Architecture Breathe Brick
Both Landscape and Architecture The recycled-plastic coupler helps align stacked bricks.

Inspired by vacuum cleaners that spin air through a vortex to separate particles, the team “came up with the idea of putting a cyclone inside of the exterior wall,” Trudell says. They developed the Breathe Brick, a porous concrete masonry unit that stacks to form an air-filtration and structural façade system.

The faceted surface of the bricks helps direct outside air to rectangular inlet ports. A cyclone filter cast directly into the concrete form causes the incoming air to spin, winnowing out particulates. Brick couplers made from recycled plastic help align the stacking modules’ two vertical shafts—one to accommodate structure reinforcement, and one to send the distilled particulates into a collection hopper at the wall base. The filtered air that passes into the cavity of the double-wythe wall system could then supply an HVAC system or an adjacent interior space directly.

Both Landscape and Architecture Breathe Brick
Both Landscape and Architecture Filtered particulates collect at the base of walls.

The jury appreciated the relatively inexpensive, low-tech solution to a worldwide problem. “Breathe Brick is a clever way of taking the heavy particulates out of the air as a byproduct of making a building,” said juror Steven Rainville.

But the jury also wondered about the practical implications of, as Joyce Hwang put it, “having thousands of Britas in your house.” To which Trudell says that the collection hoppers, which span multiple brick lengths, would need to be cleaned regularly, but not frequently.

To test the Breathe Brick concept, Cal Poly engineering students constructed a small-scale wind tunnel, 2 feet in diameter and 12 feet long, into which they blasted cornstarch and flour against four prototype modules. The units captured 30 percent of fine particles—which are defined by the Environmental Protection Agency as having a diameter of 2.5 microns or smaller, and found in smoke and haze—and as much as 100 percent of coarse particles, which measure 10 microns and larger and simulate dust. The next step for Trudell and her team is to test the Breathe Bricks’ performance in a full-scale wall.

Both Landscape and Architecture Breathe Brick
Both Landscape and Architecture Vertical shafts allow for structural reinforcement in the blocks and for dust collection to fall through.
Both Landscape and Architecture Breathe Brick
Both Landscape and Architecture The faceted geometry helps direct outdoor air into the rectangular inlets.

See all the 2015 R+D Award winners here.

Project Credits

Project: Breathe Brick, Charlottesville, Va.
Design Firm: Both Landscape and Architecture, Charlottesville, Va.—Carmen Trudell (primary investigator)
Collaborators: California Polytechnic State University, San Luis Obispo (Cal Poly)—Tracy Thatcher (consultant); Natacha Schnider, Kate Hajash, Cameron Venancio, Justin Wragg, Jennifer Thompson, Michelle Kolb (student research assistants); Rensselaer Polytechnic Institute—Kateri Knapp, Kyleen Hoover (student research assistants)

Funding: Cal Poly College of Architecture and Environmental Design's Planning, Design and Construction Institute