Researchers at the Yale School of Forestry & Environmental Studies are out to turn a tower into a wall.

With a $299,000 grant from the National Science Foundation in late July, the researchers will use the funds to create a sustainable alternative to cooling towers, devices that are used to cool water for industrial processes. The team will research “green walls” — metal frames covered in vegetation that offer myriad benefits for cooling and ecological services. The three-year project aligns with the broader movement to improve urban water use.

“We are evolving the urban environment to incorporate more plant communities and accompanying ecosystem services,” said Alex Felson, co-principal investigator and professor at the Yale School of Architecture and FES.

There are multiple services a green wall could offer in an urban setting, said James Axley, co-principal investigator and Yale School of Architecture professor. Traditional cooling towers require potable water for the sole purpose of cooling, while a green wall would use clean or dirty water to grow plants, leading to a variety of ecosystem benefits. The plants can improve the quality of the water flowing through the system, Axley said. The system could also be used for agricultural purposes, in addition to carbon capture. Finally, they provide more greenery for urban beautification.

Cooling towers are ubiquitous in urban settings, found in most industrial processes. Replacing the towers with green walls could have a widespread impact on urban areas, Axley said. While the walls are aimed for urban settings, they have potential applications for more rural areas and for use in industry, he added. The towers also require toxic chemicals to combat high mineral content.

“We want to see whether or not we can create an infrastructure that provides other valuable ecosystem services,” Felson said.

Felson and Axley will use the funds as they work to improve the design of the green wall over the next three years, with a particular focus on maximizing the water efficiency of the design.

Several students have been involved in the green wall project, specifically working with the green wall prototypes. Two environmental engineering majors, Jesse Hudkins ’13 and Scott Armbrust ’14, worked on the early stages of the thermogreen wall project for their theses and research.

Hudkins said he was attracted to the green wall’s multifunctionality, with the capacity to purify water and air, and even assist in food production. He added that the multifunctionality is what sets it apart from cooling towers.

Axley and Felson hold two provisional patents for the green wall technology.