The cold is an enemy of the range in an electric car – because in order to heat the interior, electrical energy must be drawn from the battery. This noticeably reduces the electric range. A heat pump in an electric car does help to save electricity, but it cannot work miracles. Kia has now presented several promising technologies. They are intended to prevent the interior from cooling down. The Korean car manufacturer has also developed something to combat heating up in summer. Both technologies are said to be ready for series production and were presented to the public for the first time at the company’s internal presentation “Heat Tech Day”.
Kia EV9 electric motor, 283 kW, AWD GT-line Launch Edition (electricity/reduction gear); 283 kW (385 hp): combined power consumption 22.8 kWh/100 km; combined CO2 emissions 0 g/km; CO₂ class A. Up to 505 km range.
Radiant heating saves 17 percent of energy
This includes a radiant heater that is designed to save up to 17 percent energy compared to traditional electric convection heaters. According to Kia, it consists of a heating element that generates warm rays of heat within three minutes that are aimed directly at the occupants’ legs. This provides targeted heating. It works like a heat lamp for the changing table. This means that the entire interior does not have to be heated up, which is energy-consuming, as is the case with conventional warm air heaters.
Radiant heaters heat with heat waves, which include infrared rays. Unlike convection heaters, which require air as a heat carrier and have to move it with power-hungry fans, heat rays penetrate the room air with almost no energy loss. This makes radiant heaters superior to conventional technology.
The Koreans’ heating element can be heated to up to 110 degrees Celsius. It is surrounded by a fabric that only allows infrared rays to pass through. If the device is accidentally touched, a sensor registers this and immediately reduces the temperature. The radiant heating was first installed in the Kia EV9 electric SUV. There, it produces heat rays for the interior through a total of nine heating panels.
The new technology was tested on the Kia EV9, Kia’s electric flagship.
Bild: Kia/Hyundai
Metal layer on the windows is heatable
Another development to prevent energy waste in the interior temperature control of electric cars is the glass heater. This is a thin metal coating on the windows through which 48 volts of electricity flows when it is frosty. Kia says that the invisible metal skin can defrost a window in just five minutes at an outside temperature of minus 18 degrees. This is four times faster and ten percent more economical than a conventional air conditioning system. 
Kia/Hyundai’s new nano-coated windows keep heat out and cool air in.
Bild: Kia/Hyundai
The highlight: the coating is also supposed to have an insulating effect at high outside temperatures. According to Kia, more than 60 percent of the solar energy is reflected by the applied metal. This also helps to save energy and increase the range of the electric car, as less power has to be drawn from the battery for the air conditioning.
Cooling film blocks solar heat from outside
Which brings us to the third development for controlling the temperature of the vehicle interior: At the “Heat Tech Day”, Kia and Hyundai presented a coating for the windows that is designed to make it easier to cool down in the summer heat. The material, called the “cooling film”, is extremely thin – its thickness is in the nano range – and consists of three layers: two reflect sunlight, one blocks infrared light. The cooling film repels heat rays from the sun outside, while the nano layer retains heat inside. The invention was first presented a year ago, and according to the manufacturer, it is now ready for series production.
The best electric cars up to 48,000 euros
Kia has tested the effectiveness of the coating on various vehicle models. Two identical models were tested. One had all the windows covered, the other did not. While the unprotected car heated up to 48.5 degrees Celsius in the interior, the developers only recorded up to 36.5 degrees Celsius in the other.
