Tesla last week outlined some of the details that distinguish the heat pump systems that are now included in its vehicles.
The electric vehicle maker claims that their design works well in very cold weather where other heat pumps don’t work.
Tesla claims that, depending on the exact situation, its cars can use a quarter less energy with a heat pump system than without, to keep the cabin warm. Overall, it can help reduce energy consumption when traveling in cold weather by up to 20%, Tesla says — although it’s unclear if this specifically refers to energy consumption in the cabin.
Tesla is by no means the only automaker to find that heat pump remedy EV reduces cold weather range. It was against technology years ago.
Before heat pumps, Tesla strategically used waste heat from the engine and power electronics to help warm up the battery, and claimed to have increased cold-weather range without adding complexity. of the heat pump. But the company changed its mind with the heat pump making its debut in the Model Y.
Tesla heat pump
Tesla heat pump
Tesla heat pump
The answer seems to be that it figured out how to make addition less complicated. It has designed a so-called supermanifold that combines all refrigerant channels and the coolant channels can be separate components. As explained in this video, instead of redesigning the cooling ring, Tesla integrated the heat pump with an “octagonal valve” that can rotate to a different position depending on the operating mode.
How does a heat pump work?
Tesla’s video says heat pumps are a bit like installing an air conditioner, carrying heat from a cooler environment (inside) to a warmer environment (outside), only the opposite.
Unlike internal combustion vehicles, EVs do not have an engine that emits waste heat that can be used to warm the cabin. Resistance heating, like the one used for space heaters, toasters, or hair dryers, consumes a lot of energy.
Heat pumps move heat around rather than create it, and the physics sound almost magical: A carefully selected gas—the refrigerant—removes heat from its surroundings as it is compressed into gas and then release heat as it condenses back into a liquid.
Tesla Model plaid heat and heat pump
Heat pumps are one of the keys to reducing EV reduces cold weather range because of that energy. On the basis of energy in, energy out, according to Bosch, one of the heat pump manufacturers, a heat pump with a capacity of 1 kW will produce the equivalent of 2 to 3 kW of heat. Mahle, another supplier, says its heat pump can recover 20% of losses in the cold weather range.
There are some caveats to this. Heat pumps involve a lot of cost and complexity; they can generate some noise that disrupts a quiet EV experience; and they don’t usually give results as quickly as resistive heating. So owners can only see efficiency results on longer road trips—when they’ll help increase range and make it easier to reach the next charger without compromising comfort in the cabin.
The essential piece to avoid the winter gloom
Increasingly, companies are concluding that it’s worth the trade-off. For example, General Motors has emphasized that its real-world advantage is why it decided to include heat pumps in all upcoming GM EVs.
There are many new ways to configure the system, especially to increase cold weather. Rivian is in the process redesigned its thermal system to include a heat pump, and the latest Heat pump for Hyundai and Kia modelsHeat is removed from a series of drive units that convert the liquid refrigerant back to a gaseous form, reducing load and increasing energy efficiency.
Systems with a heat pump combine it with resistive heating, to quickly defrost/defrost the windshield and heat the cabin quickly when needed, then it passes the baton when it can get to the pump. heat. As the system diagrams in the Toyota Prius Prime highlight, they can get very complicated.
Heat Pump Toyota Prius Prime
This isn’t the first time we’ve seen Tesla’s heat pump design. In 2020, production expert Sandy Munro, of Munro & Associates, known for his insights, posted a video about new ingredients.
Tesla’s own design isn’t entirely without problems, either. The company had to fix an issue with a heat pump valve that wasn’t working properly, leading to a drain on refrigerant in the system and potentially causing some windows to fog up. This Tesla heat pump recall The campaign, which affected nearly 27,000 vehicles from the 2020 to 2022 model years, was fixed with an over-the-air update.
