'Living walls' can benefit area by helping clean the air

Indoor plants would provide beauty as a green feature being considered for an expanded Greenbelt Cultural Center, but they also would literally be put to work cleaning the air.

Watering the plants would take on an entirely new meaning with the construction of a "living wall" at Greenbelt, which is operated by the Lake County Forest Preserve District.

The system being considered would be among the first of its kind in the United States to use plants to filter and clean volatile organic compounds from indoor air, an emerging technology supporters say would have many benefits.

The living wall is the last major construction contract to be considered for the recently started $5.6 million expansion of the facility in North Chicago.

"It's not just a wall with plants in it," explained Katherine Hamilton-Smith, the district's director of cultural resources. "Rather, it is tied into the whole air handling system of the building. The root systems actually eat the toxins in the air. It cleans the air of over 80 percent of volatile organic compounds."

Volatile organic compounds are indoor pollutants that can arise from solvents, building materials and carpets.

With an initial cost of $148,000, not counting ongoing maintenance, the green idea has cleared several forest-board committees and next will go before the finance committee on Thursday. The full board could vote on the concept Sept. 14.

At an estimated $600 per year, the energy saved by having the wall would be minimal. But supporters cite the clean air attributes and the wall as a centerpiece feature and educational tool as reasons to proceed.

"We're proud to have such a rare environmental attraction in the expanded Greenbelt Cultural Center," said Commissioner Angelo Kyle, who chairs a special Greenbelt expansion committee.

The living wall was suggested by Serena/Sturm Architects, which designed the "sister" building that will more than double the size of the popular Greenbelt facility.

"The main thing is it provide a natural means of removing volatile organic compounds from the air and it will tie in with our educational programming," said Mike Fenelon, the district's director or planning, conservation and development. "It'll be sort of a conversation starter regarding environmental education."

At about 510 square feet, it would occupy the majority of the south side of the new program room as a self-contained feature built in front of the traditional structural wall.

Plants would be installed not in soil but in a mesh-like growing medium, giving the roots something to hold onto but leaving them exposed to do their work. This medium is attached to an array of perforated air pipes that connect to the building's air handling system.

Nedlaw Living Walls is the Canadian manufacture of the system being considered for Greenbelt. The firm describes itself as the only one to use plant walls as biofilters to control indoor air quality.

As explained by the company, "dirty" air is forcibly drawn into the system and comes in contact with water that is constantly flowing within the wall. Pollutants move from the air to the water where they dissolve and are "attacked" by the microbes on the plant roots.

"In essence, we mimic indoors what happens outdoors every day," according to information on the company website.

Having plants on a desk or grouped on a wall would have limited impact because pollutants are not drawn to the root zone where the breakdown occurs, according to the company.

"Green plants themselves don't do much for air quality," said Alan Darlington, company president.

Fewer than 10 living walls have been installed to date in the United States. They include one in a business incubator building in Albuquerque, N.M. installed about 18 months ago as part of a $10 million project.

Plants grow between two layers of what looks like thick Fiberglas, said Doug Lee, who manages the building for WESST, the company that runs the incubator.

He said it has improved the working environment by adding humidity in a dry region. Maintenance is about $300 a month, he said, and the company had to buy a lift truck to access the top of the wall.

All in all it has been a good addition, Lee added.

"We have people coming into the building who just want to look at the wall," he said.