nissan's white cooling paint for cars can reduce cabin temperature and air-conditioning use

Nissan trials its white cooling paint for cars

Nissan has put its recent white cooling paint for cars to the test, which can help lower cabin temperatures and reduce air conditioning use. The car manufacturer developed the substance with Radi-Cool, a specialist in radiative cooling products. The duo uses metamaterials for the white cooling paint, which are man-made materials engineered to have properties not typically found in nature or common materials. Nissan started its 12-month test for the paint in November 2023, trialing it at Tokyo International Air Terminal at Haneda, in collaboration with Japan Airport Terminal Co., Ltd., Radi-Cool Japan, and All Nippon Airways (ANA) airport service.

The white cooling paint was applied to a Nissan NV1000 service van. The airport was a conducive space for testing since the open-air setting could expose the vehicle to a high-temperature environment. Nissan parked two vehicles side-by-side in the sun, with only one of them bearing the paint. While the car manufacturer is still in its testing phase, results, including those from the airport, show that the white cooling paint can reduce the exterior temperature by up to 12 degrees Celsius and the interior temperature by up to 5 degrees Celsius. Nissan says that the paint’s performance is more noticeable when a vehicle is parked in the sun for an extended period.

all images courtesy of Nissan

Man-made ‘metamaterials’ with particles that deflect sunlight

Nissan’s white cooling paint uses man-made ‘metamaterials’ developed in-house by the car manufacturer. It contains particles that reflect near-infrared rays from sunlight, which are a type of sunlight that causes heat. These rays can make traditional paint get hot because they cause the paint molecules to vibrate and produce heat. However, the metamaterials create electromagnetic waves that counteract or cancel out the sun’s rays. Instead of just reflecting sunlight, they actively work against the heat from the sun, pushing the energy away from the car and into the air. As a result, less heat is transferred into the car’s surfaces, such as the roof and hood.

White cooling paint isn’t new, according to researchers led by Dr. Susumu Miura, senior manager and expert at the Advanced Materials and Processing Laboratory, Nissan Research Center. This kind of coating has been used in architecture, and the aircraft industry has even explored it, but it has not been used extensively for cars until now, the Nissan team adds. However, there are challenges, such as the thickness of normal paint. Traditional paint is also applied with a roller, which isn’t ideal for the researchers. There is also a possibility that the resulting paint may not have a clear topcoat, which could leave a chalky residue when touched.

Nissan has put its recent white cooling paint for cars to the test

Cooling paint resistant to peeling, scratches, and chemicals

The Nissan researchers are determined to find solutions to these challenges. They want their white cooling paint to have a clear, glossy topcoat to protect the paint and give the cars a shiny finish. This has not been done with any radiant cooling paint before, the team says. Additionally, they aim for the paint to be applied with a spray gun instead of a roller. The researchers tested over 100 samples before finding the right formula. They are currently working with a paint that is 120 microns thick (about six times thicker than regular car paint).

Although it is thicker than expected, the researchers are now focusing on finding ways to make the substance thinner. So far, the white cooling paint they have developed can resist salt, chipping, peeling, scratches, and chemical reactions. The Nissan team has also experimented to make sure that the color remains consistent and that it can be repaired if needed. In addition to making the paint thinner while maintaining its cooling effectiveness, the Nissan team hopes to offer this paint in different colors and make it available for customization. As of the publication of this story, Nissan’s white cooling paint is still in its testing phase.

the car paint can help lower cabin temperatures and reduce air conditioning use