Heat pump

What is a heat pump in a car?

The heat pump (HP) is a thermal comfort equipment that has become a technological standard on many modern electric vehicles. Its role is to heat or cool the cabin much more efficiently than a conventional system. While an internal combustion engine produces a large amount of waste heat, which is easily recoverable to heat the cabin, an electric motor produces very little. Manufacturers therefore had to find an energy-efficient solution to ensure thermal comfort without drastically impacting battery range, especially in winter. The heat pump is that solution.

How does an automotive heat pump work?

The operation of a heat pump is ingenious and relies on the same principles as those of a refrigerator or an air conditioning system. It does not create heat, but moves it from one place to another using a refrigerant fluid.

• In heating mode: The system captures the calories (thermal energy) present in the outside air, even at negative temperatures. The refrigerant, in a cold, liquid state, absorbs this heat and evaporates. A compressor then increases the pressure and temperature of this gas, which then flows to a condenser located in the cabin ventilation system. As it condenses, the gas releases its heat, which is diffused to warm the passengers. The fluid, having returned to a liquid state, passes through an expansion valve to lower its pressure and temperature, and the cycle starts again.
• In air conditioning mode: The cycle is simply reversed. Heat is captured from inside the cabin and rejected outside, thus cooling the interior air.

This ability to "multiply" energy (for every 1 kWh of electricity consumed, a heat pump can deliver 3 to 4 kWh of heat) gives it a coefficient of performance (COP) well above 1, unlike resistance heaters which have a COP of 1.

The concrete benefits of the heat pump

The integration of a heat pump offers major benefits for the driver and passengers of an electric vehicle.

• Range preservation: This is the number one advantage. In winter, resistance heating can consume several kilowatts and reduce the range of an electric vehicle by 20% to 40%. Thanks to its efficiency, the heat pump divides this consumption by 3 or 4, limiting the range loss to just 10-15%. This is an essential purchasing criterion for motorists living in cold regions.
• Optimized comfort: Temperature rise is often faster and the heat distributed is more uniform. Furthermore, the system can thermally pre-condition the cabin (heating or cooling) while the vehicle is charging, without drawing power from the traction battery.
• Battery thermal management: On the most advanced systems, the heat pump is integrated into the battery thermal management circuit. It can thus warm the battery before fast charging in cold weather to improve charging speed, or cool it during intensive use to preserve its lifespan.

Which vehicles are equipped with a heat pump?

Initially reserved for high-end models, the heat pump is becoming more democratized and is now offered, as standard or optional equipment, on a wide range of electric vehicles. It can be found notably on popular models such as the Renault Megane E-Tech, the Peugeot e-208/e-2008 (on the new generations), the Volkswagen ID.3/ID.4, the Hyundai Ioniq 5, the Kia EV6, as well as the Tesla Model 3 and Model Y. However, it is crucial to check the technical specifications of the specific model and trim level you are interested in, as it is often bundled into an optional "Winter Pack" or "Comfort Pack" on entry-level versions. For any electric vehicle buyer, ensuring the presence of this equipment is a true guarantee of versatility and daily peace of mind, regardless of the season.