Incorporating zigzag patterns into building walls can help cool overheated buildings, research has found.
Buildings now account for approx 40% of global energy consumption, which contributes more than a third of global carbon dioxide emissions.
A significant part of this energy comes from air conditioning use. Scientists expect this figure to double by 2050 if left unchecked.
As the planet continues to warm, the demand for cooling in buildings continues to increase.
In response to this growing challenge, scientists have explored passive cooling solutions that do not rely on energy consumption.
A research team led by Qilong Cheng at Columbia University in New York has developed a promising solution which can help reduce energy consumption by redirecting the sun’s energy away from buildings.
Cheng’s team proposed a structural wall design with a zigzag pattern that could reduce a building’s surface temperature by up to 3C compared to flat walls, without consuming any energy.
“With this kind of design, we can have a cooler building,” Cheng said. “So we can reduce energy consumption for cooling.”
The design consists of walls with a series of protrusions that create a zigzag shape when viewed from the side.
This configuration takes advantage of radiative cooling – a passive cooling strategy that reflects sunlight and emits long-wave infrared radiation through the Earth’s atmosphere into outer space.
Radiative cooling has attracted attention over the past decade as an energy-efficient way to reduce cooling needs.
Common strategies, such as painting roofs white to reflect sunlight, have been effective for horizontal surfaces, but are less ideal for vertical walls, which also absorb heat from the ground.
The zigzag wall design addresses these challenges by creating surfaces that radiate heat into the atmospheric transparency window and reflect infrared heat, rather than absorbing it.
Although this innovative cooling method shows promise for warmer climates, it can increase heating requirements in colder regions during the winter.
To address this, Cheng and his colleagues proposed an adaptable design with hinged “fins” that could be raised in winter to increase heat absorption and lowered in summer to reduce it.
