Fraunhofer Thin-Film Heater Ideal For Electric Cars

Fraunhofer thin film heater is ideal for electric cars.

Heat is a problem for electric car drivers. If you crank it up too high, it kills your range. Many EV drivers simply add an extra sweater, a ski parka, a scarf, gloves, and fur-lined boots to make it to work in the morning without freezing to death. But now there may be a better way. The Fruanhofer thin-film heater quickly provides comfortable warmth in electric cars — a blessing on short trips on frosty winter mornings.

The heater uses a film that is coated with a very thin layer of conductive carbon nanotubes (CNTs). “The film is glued to the inner door trim and generates a comfortable warmth there in the area of the armrest within a very short time,” says Serhat Sahakalkan, project manager at Fraunhofer, which is located in Stuttgart, Germany.

The Fruanhofer thin-film heater functions in accordance with the Joule principle: When electricity flows through the film, it comes across a natural resistance between the individual nanoparticles. These “collisions” generate heat. Extremely thin film saves energy and costs compared to conventional electric resistance heaters of the type used in electric cars. Ordinary heaters employ a copper wire embedded in silicone mats, according to

The Fraunhofer thin-film heater has several advantages. It is less bulky than conventional electric heaters, which take up quite a lot of space in the interior of the cars they are installed in. By contrast, the Fraunhofer film heater consists of a layer of conductive material that is only a few micrometers thick. It can be flexibly applied to most surfaces. Its low weight is an advantage for electric cars, where every kilogram of weight reduces available range. The film heater is also cost competitive with conventional copper-wire heaters.

The carbon nanotubes have a low heat storage capacity, which means the heat generated is released directly released into the surrounding space. Also, the heat is evenly distributed over the entire surface of the film, which increases efficiency considerably. When the driver turns the film heater off, it cools down quickly. “These fast response times are ideal for short distances such as urban trips,” Sahakalkan says.

The Fraunhofer thin-film heater sounds like it would have many other uses in automobiles, homes and offices. Many drivers let their cars idle for several minutes on cold mornings, waiting for the coolant to warm up enough to put some heat into the interior. The technology could also allow seldom-used rooms to be heated quickly and efficiently. It will be interesting if Fraunhofer finds any takers for its new thin-film heater when it presents it next week at the Frankfurt Auto Show.

Steve Hanley

Closely following the transition from internal combustion to electricity. Whether it's cars, trucks, ships, or airplanes, sustainability is the key. Please follow me on Google + and Twitter.