These days air pollution in cities is a big problem, and as a result, buildings that help alleviate that problem are all the rage.
In recent years though, designers have started to move beyond simply reducing a building's emissions and started to work with techniques that actually remove pollutants from the air, through systems such as Nemesi's "photocatalytic" facade for the Italy Pavilion at the 2015 Milan Expo which captures and reacts with pollution in the presence of light.
However, in most cases these new technologies have been chemical, only affecting the air that physically comes into contact with them. What if buildings could take a more active role in pulling in pollutants from the sky? What if they could work a little more like a vacuum cleaner? This was exactly the inspiration behind the Breathe Brick developed by Carmen Trudell, an assistant professor at Cal Poly San Luis Obispo's school of architecture and founder of Both Landscape and Architecture.
The Breathe Brick is designed to form a part of a building's regular ventilation system, with a double-layered facade of the specialist bricks on the outside, complemented by a standard internal layer providing insulation. At the center of the Breathe Brick's function is cyclone filtration, an idea borrowed from modern vacuum cleaners, which separates out the heavy pollutant particles from the air and drops them into a removable hopper at the base of the wall.
The system is composed of two key parts: concrete bricks, and a recycled plastic coupler, which both helps to align bricks and creates a route from the outside into the brick's hollow center. The concrete bricks themselves feature a faceted surface which helps to direct airflow into the system, and a separate cavity for inserting steel structure.
The Breathe Brick can function with both mechanical and passive ventilation systems, as the brick simply delivers filtered air into the wall plenum; this air can then be delivered to the building interior through mechanical equipment or through trickle vents driven by passive systems such as stack ventilation.
In windtunnel tests, the system was found to filter 30% of fine particles (such as airborne pollutants) and 100% of coarse particles such as dust. As the entire system is relatively inexpensive, the Trudell posits the Breathe Brick as a way to lower pollution levels in developing countries, where rapid expansion of industry and less stringent environmental regulations often cause problems.