Naama Barak
May 9, 2023

Vertical green living walls are not just terribly Instagrammable, but also serve the almost equally important function of lowering the temperature around them and helping cut down on energy use, according to a recent study.

Researchers from the Hebrew University of Jerusalem examined green walls in a closed room for a year and a half, monitoring environmental indicators such as carbon dioxide levels, temperature, humidity, and the quality and pH levels of the irrigation water.

According to their study, published in the Building and Environmentjournal, certain plants can reduce the need for ventilation and air conditioning by using carbon dioxide from the air and transpiring water vapor into the room, thus reducing CO2 levels and cooling the air around the green wall.

The green walls, the researchers noted, reduced the need for air circulation by some 20 percent and lowered the temperature near the plants by about three to five degrees Celsius.

“Heating, cooling and ventilation systems of residential buildings are responsible for 27 percent of energy consumption and 17 percent of carbon dioxide emissions in the world,” explained study leader David Helman.

“In addition to this, the high energy consumption in cities is also responsible, among other things, for the ‘urban heat island’ phenomenon, a situation in which the temperature inside the city is between one and three degrees Celsius higher than the surrounding rural environment,” he said.

“The study’s results could encourage building planners and office owners to use plants to save energy and money while still meeting the required standard for ventilation in public buildings,” Helman added.

“In the near future, we plan to expand the research and publish a system based on artificial intelligence and image processing that will make the process of planning and maintaining the green wall simpler and more accessible, so that some of the routine maintenance operations can be performed automatically.”

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