Interior wall brings breath of fresh air to home of the future
Biowall, a Purdue University project, is showing promise in the use of a wall of plants to clear the air within inhabited built spaces
More than 3.8 million deaths worldwide each year are blamed on household air pollution, and scientists are turning to many strategies to try to clean the air in homes and offices, including the use of everyday plants. A Purdue University project called the Biowall is showing promise in the use of a wall of plants to clear the air within built spaces inhabited by humans.
“The Biowall is an eco-friendly air filtration system that can be used in residential buildings to improve air quality,” says Bill Hutzel, a professor of mechanical engineering technology in Purdue’s Polytechnic Institute, who leads the research team. “We combine Purdue expertise in building design, engineering and agriculture to help with the home of the future.”
This system uses plants grown in a loosely packed growth media, allowing air to pass through the media. The plant's roots absorb volatile organic compounds from the passing air, removing these compounds from circulation. The system is integrated into the return duct of a HVAC unit, so the biowall can affect the air quality for the entire home.
“I come from the design side, where we know that energy-efficient homes are very well insulated - but they also trap and accumulate volatile organic compounds like toluene,” Hutzel adds.
In 2014, Whirlpool Corp., along with Purdue, transformed an existing home near Purdue’s campus into a research laboratory and sustainable living showcase called the ReNEWW house. Purdue researchers installed the Biowall in the ReNEWW house to monitor the performance of the biofilter, the health of the plants present and comfort of residents.
“I work with data from NASA and other research organisations to figure out which plants are likely to perform the best in keeping the air clean inside the home,” discloses Danielle LeClerc, an undergraduate student who works on the Biowall team. “It is interesting to incorporate data from a space agency like NASA into the everyday home of the future.”
A video about the Biowall project is available at https://youtu.be/T2c1AFcikUQ.
The video tells us that "indoor air quality kind of flies under the radar, but it’s a big topic in buildings that, as we make them more efficient, we invite problems in other areas. Our version of a biowall is plants integrated with the ventilation system in a highly efficient building to kind of have a two-fold purpose. Number one, it has a natural aesthetic that appeals to some people and, number two, it’s got that functional characteristic where it can improve indoor air quality in buildings.
"Plants have the ability to metabolise airborne contaminants, and it’s more than just photosynthesis. We all know that plants can take in carbon dioxide and light and turn that into oxygen, but there’s a lesser exploited phenomenon where the root zone of the plants hosts a microbial community. Those microbes have the ability to break down common airborne contaminants like toluene, formaldehyde, and even benzene.
"We’re pretty close to being at the point where we’re trying to move it into a pre-commercialisation stage where we’re more focused on reducing the cost, improving the reliability, and probably working more closely with home builders in terms of 'you tell us what you need'. What can you sell to your customers? If you can do anything to make a living space more accommodating, more healthy, more comfortable, you’re going to have happier, healthier, more productive people."