Hyundai Motor Company and Kia Motors Corporation have recently revealed new details of their innovative heat pump system, deployed in Hyundai and Kia’s global electric vehicle (EV) line-up to maximize their all-electric driving range in low temperatures.
Hyundai and Kia’s heat pump is a heat management innovation that maximises the distance that Hyundai and Kia EVs can travel on a single charge, scavenging waste heat to warm the cabin. It enables EV drivers to heat their car’s cabin in cold weather without significantly impacting electric driving range, unlike other EVs.
The technology was first introduced in 2014 on the first-generation Kia Soul EV. Comprising a compressor, evaporator and condenser, the heat pump captured waste heat given off by the vehicle’s electrical components, recycling this energy to heat the cabin more efficiently. The technology meant the Soul EV’s 180 km electric range was protected in cold weather driving conditions.
How Does This System Work?
The heat pump harvests significantly more energy by recycling additional waste heat not only from power electrics (PE) modules. The new system scavenges waste heat from an increased number of sources for optimum cold-weather EV range. These innovations mean that Hyundai and Kia EVs offer a more consistent range in temperatures where other EVs start to see a significant decline in the distance possible from a single charge.
The industry-leading heat pump system has now been developed further for new EVs from Hyundai and Kia. Equipped with the latest heat pump technology, the Kona Electric proved this in a recent test in Norway, the most advanced EV market in the world. It now harvests significantly more energy by recycling additional waste heat not only from power electrics (PE) modules (such as drive motors, on-board chargers, and inverters) but also from the battery pack and slow charger.
This captured energy improves the efficiency of the HVAC (heating, ventilation and air conditioning) system, recycling it to more efficiently heat up the cabin and minimize battery power consumption. By reducing the load on the battery, the heat pump cuts energy consumption from the HVAC system, maximising the available electric driving range of the car.
The system uses the heat generated by these components to vapourise refrigerant from liquid to gas form. High-pressure gas is discharged from the compressor and forced into a condenser to be converted back into a liquid. This process generates additional heat energy that is recovered by the heat pump and used to warm the cabin.
Kona Electric wins Norwegian real-range validation test
The Norwegian Automotive Federation (NAF) recently compared 20 EVs in cold and warm weather conditions to identify models with the most consistent driving range and charging performance. The test monitored the performance deviation of each vehicle in cold conditions compared to quoted manufacturer figures.
The Kona Electric took first place, travelling 405km in the cold – compared to the 449km quoted under WLTP combined cycle testing conditions (23°C / 73°F). In severe cold weather, the Kona Electric offered 91 percent of its WLTP combined cycle range, deviating just 9 percent from its claimed all-electric driving range.
EV Cabin Heating: How Does It Work?
The heat pump is one of a number of innovations found in Hyundai and Kia’s current generation of EVs, with heat management also used to realise major improvements in EV battery packs. A water-cooling system for Hyundai and Kia’s EV battery packs, rather than conventional air cooling, have yielded further increases in range without increasing physical dimensions. This development means battery cells in Hyundai and Kia EVs can be packaged much more tightly, with water-cooling channels taking up less space than air-cooling channels, increasing battery density by up to 35 percent.
This innovation means the latest EVs from Hyundai and Kia offer around twice as much driving range and battery capacity compared to their first-generation EVs – and are capable of travelling significantly further on a single charge. For example, the first-generation Soul EV offered owners an electric driving range of around 180km from a single charge of its 30kWh lithium-ion polymer battery pack. The second-generation Soul EV, with a 64kWh battery occupying a similar amount of space, is capable of traveling up to 386km on a single charge.
Under its ‘Strategy 2025’ plan, Hyundai Motor aims to sell 670,000 battery EVs and FCEVs (fuel cell electric vehicles) annually by 2025. Kia’s mid- to long-term strategy, dubbed ‘Plan S’, will see the brand’s line-up grow to 11 EVs over the same timeframe.