​We all know that trees help to improve our air quality. Absorbing toxins, reducing CO2 levels and providing shade are well-known benefits of trees, and many initiatives are in place to increase urban forested areas. However, there is an interesting fact to consider. According to the U.S. EPA, the average American spends 90% of their time indoors, where those benefits of outdoor trees aren’t nearly as impacting. In fact, pollutants are estimated to be two to five times higher indoors than outdoors and account for several billion dollars of health costs nationally. Indoor air needs to be cleaned too. This is the problem that Purdue’s BioWall team hopes to solve.

The project began in 2009 as part of a fully self-sustainable house called the INhome. In 2011, INhome competed against 20 other teams in the United States Department of Energy’s Solar Decathlon and scored second place, largely due to its most distinguishable feature, the BioWall. The BioWall was integrated into the return duct of INhome’s air conditioning system, filtering the air inside the home through the roots of goldon pothos and other species of ivy that are known to have a strong effect on air quality.

Today, the BioWall team is in the process of testing out an updated version of the BioWall. Prototype designs are being tested to improve the air cleaning qualities as well as the lifespan of the plants. Bypass tubes are being implemented to lessen the amount of air passing over the plants’ roots, allowing them to dry out slower and live longer. Eventually, the team would like to put out a consumer version in the next few years for about $2,000. It’s a lofty goal, but the team believes they can succeed and bring affordable and self-sustaining indoor air cleanliness to homes around the world.

For more information, check out the BioWall team’s website.

Resources
BioWall, Purdue University
Office of University Sustainability, Purdue University
Questions About Your Community: Indoor Air, United States Environmental Protection Agency

William Hutzel, Professor of Mechanical Engineering Technology
Purdue University