To Beat the Heat, Think Zigzagging Wall Assemblies

A small change in wall design could cut a home’s indoor temperature by more than 37 degrees Fahrenheit.

Incorporating zigzag patterns into walls could help cool overheated buildings, according to researchers at Columbia University. The patterns redirect the sun’s heat away from a building and can reduce its surface temperature by up to 3 degrees Celsius (37.4 degrees Fahrenheit) compared with flat walls, without consuming any energy.

The design consists of walls with a series of protrusions that create a zigzag shape when viewed from the side. This configuration utilizes radiative cooling—a passive strategy that reflects sunlight and emits long-wave infrared radiation through the Earth’s atmosphere into outer space. 

Better-known strategies, such as painting rooftops white to reflect sunlight, have been effective for horizontal surfaces but are less ideal for vertical, according to research team leader Qilong Cheng.

Although it is still under research, the design could be a huge plus for the environment. Buildings are now responsible for approximately 40 percent of global energy consumption—much of which comes from air conditioning usage. Buildings also produce more than one-third of all global carbon dioxide emissions.

But this cooling method could increase heating demands in colder regions during winter. To address this, Cheng and his colleagues have proposed an adaptive design featuring hinged fins that can be raised in winter to increase heat absorption and lowered in summer to reduce it. 

Click here to read more building science posts .