For EVs, which are driven by an electric motor rather than an engine, heat management is very important not only for air conditioning in the cabin, but also for the battery, motor, and inverter. The battery, in particular, must be kept in the proper temperature range, or performance may be degraded and safety issues may arise. For example, ultra-fast charging may cause the battery to become too hot, resulting in a rupture or similar. To resolve these issues and properly manage EV battery temperatures, Sanden has developed integrated thermal management system (ITMS), which is being proposed to automotive manufacturers around the world.

In EVs, the power consumed to run the air conditioning equipment has a significant impact on electricity costs (power efficiency) and cruising distance. In conventional engine-powered vehicles, the exhaust heat generated by the engine can be used for things like heating the cabin, but EVs do not have an engine. Since electric heaters are used for heating, the amount of electricity available for driving is reduced by the amount used for heating. In fact, heating an EV with an electric heater consumes as much electricity as it needs to drive, resulting in a significant decrease in cruising distance. In addition, power is consumed for air conditioning even when the vehicle is stopped on a snowy day or in a traffic jam, so the battery depletes rapidly. Drivers are sure to feel uneasy in such a situation.

Efficiency can be improved by installing a heat pump system instead of electric heaters. A heat pump system is energy-efficient air conditioning system that draws heat from the outside air. It is also used in home air conditioners and can efficiently supply heat energy using less electricity. Depending on conditions, heat pumps consume about half the power of electric heaters, and Sanden’s ITMS can operate more efficiently because it uses heat from the drive motor and other sources.

Briefly, a heat pump system consists of a compressor, a condenser, an expansion valve, an evaporator, and piping that connects them. Then, there is a refrigerant, which can evaporate even at low temperatures, circulating in the piping. The refrigerant is compressed, liquefied, and evaporated while taking in heat from the outside air, and this process is repeated to cool or heat a space. This mechanism, whereby thermal energy is generated by capturing heat from the outside air and the drive motor, allows for transfer and utilization of heat approximately 2 to 6 times greater than the power consumption. This means that an EV can be heated using smaller amounts of electricity, reducing battery consumption and ultimately extending the EV’s cruising distance. If you want to know more about the principle behind heat pumps, you can find many references by searching online for a “p-h diagram.”

Although automotive manufacturers are attempting to address this by, for example, installing higher-capacity batteries, increasing battery capacity alone will not solve the problem of ever-increasing power consumption. We believe that an integrated thermal management system (ITMS), which includes efficient heat pump technology, can further increase the cruising distance of EVs by providing comfort for both the occupants and parts like the battery.