Another Car-Cooling Tech Emerges

Nissan is following an Asian competitor in recent quests to lower vehicles’ interior temperatures.

The Japan-based automaker is testing a paint with “embedded metamaterial” that it says keeps down cabin temperatures. The aim, if trials are successful, is to offer it as a vehicle option.

The research follows South Korean rival Hyundai’s development of a window tinter that it says cools interior vehicle temperatures. The automaker announced the Nano Cooling Film this past spring, saying it can lower cabin heat by dozens of degrees.

Nissan created its vehicle paint with Radi-Cool, which it said specializes in radiative cooling products.

The coating contains metamaterial, which the company describes as “synthetic composite materials with structures that exhibit properties not usually found in nature.” Encyclopedia Britannica says such material has “electromagnetic properties.”

Nissan started a 12-month trial of the paint in November, applying it to a Nissan service vehicle at the Haneda Airport in Tokyo, for maximum sun exposure, and calls the results so far “impressive.”

Parked next to a vehicle with traditional paint, Nissan said the specially treated car’s exterior surface temperatures have been about 22 degrees lower and its interior temperatures down by as much as nine degrees.

The paint’s technology reflects sunrays and sends out electromagnetic waves that deflect sunrays' energy from the vehicle to the atmosphere, says Nissan, which pointed out that radiant cooling is already used to cool buildings.

"My dream is to create cooler cars without consuming energy" said Susumu Miura, who’s been leading the Nissan paint development for three years. "This is especially important in the EV era, where the load from running air-conditioning in summer can have a sizable impact on the state of charge," he said.