How Do Electric Cars Make Heat?
Electric cars produce heat primarily through electric heaters and heat pumps. Unlike traditional internal combustion engine (ICE) vehicles that generate heat as a byproduct of engine operation, electric vehicles lack this source of incidental heat.
Today we are looking at both the old methods and new ways that car makers ensure that you’ll have plenty of warmth in the dead of winter.
Conventional Electrical Heating Elements
Electric vehicles utilize a method comparable to the electric baseboard heaters in homes to generate warmth.
Essentially an electrical resistor is used; when electric current is passed through, it generates heat.
This is a straightforward and rapid approach to provide heat but is not energy efficient, leading to a significant reduction in driving range, especially in colder conditions.
- Pros: Quick heating, cost-effective
- Cons: High electricity consumption, reduced range
Self-Regulating Electrical Heaters
A more advanced electrical heating system employed in newer electric vehicles is based on self-regulating heating technology.
Initially, this system consumes a considerable amount of power, but as it warms up, the resistance increases, and power usage decreases, preventing excessive energy draw from the battery.
- Pros: Prevents thermal runaway, more efficient than conventional heaters
- Cons: Higher initial power consumption
Heat Transfer Systems
The most efficient heating method in electric vehicles is a heat transfer system or a heat pump.
Unlike a traditional heater, it moves existing heat from the outdoor air into the vehicle’s cabin, significantly enhancing energy efficiency even in colder weather.
- Pros: Great efficiency, optimal energy usage
- Cons: Performance varies with outdoor temperature
Not every EV comes equipped with a heat pump system. This feature’s availability may influence the car’s performance in frigid environments as well as its price. For instance, some models may rely on self-regulating heaters when the heat pump’s effectiveness diminishes at significantly low temperatures.
Evaluating Vehicle Cabin Heating Approaches
EVs manage cabin heating during colder weather through various technologies, diverging notably from gasoline-powered cars that utilize waste engine heat.
You might wonder how an electric vehicle ensures warmth without relying on the internal combustion engine’s heat production.
The most mature, yet least efficient form of heating in EVs stems from resistive heating systems.
Similar to your home’s electric baseboard heaters, these systems generate warmth by passing electricity through resistive elements.
While cost-effective and rapidly providing heat, they significantly decrease driving range due to their energy consumption intensity, notably in earlier EV models like the first-generation Nissan Leaf.
Modern electric vehicles frequently employ Positive Temperature Coefficient (PTC) heaters.
At startup, these heaters demand high energy, but as they warm up, the resistance increases, curbing the energy pull from the battery.
This not only prevents overheating, reducing fire risks but also economizes power usage after reaching the set temperature.
For a peak in efficiency, however, heat pumps take precedence. Differing from heaters, these pumps transfer ambient heat from the outside air into the cabin instead of generating heat through electricity.
While the efficacy of heat pumps scales with external temperatures, often most models will include an auxiliary heating system, such as a PTC heater, to provide warmth when the external temperatures drop severely.
Yet, not all recent EVs integrate heat pumps, such as the Chevrolet Bolt, because adding this technology could inflate vehicle costs.
The decision to include a heat pump balances additional costs against potential range benefits, necessitating careful consideration by manufacturers and consumers alike.
Recapping Electric Vehicle Cabin Heating Methods
Your electric car manages cabin heating differently than traditional gas-powered cars, ensuring your comfort during the colder months without relying on an internal combustion engine. Let’s explore the heating technologies available in modern EVs.
Older Technology: Resistive Heating
- Initial EV Heating Method: Older electric cars employed resistive heating, similar to the electric baseboards in homes.
- Operation: It involves passing current through a resistor, which then heats up.
- Pros: The simplicity and low initial costs are its main benefits.
- Cons: It is a significant energy consumer, leading to reduced vehicle range—especially noticeable in first-generation Nissan Leafs during winter.
Modern Methods: PTC and Heat Pumps
PTC (Positive Temperature Coefficient) Heaters
- Mechanism: They are advanced resistors that decrease power use as temperature rises.
- Efficiency: Offers more efficient heating by drawing high power initially and then reducing consumption once the optimal temperature is reached.
The Kia Niro EV is an example of this system, showcasing how advanced resistive heaters manage efficiency better.
Heat Pumps
- Most Efficient: A cutting-edge approach for cabin heating in EVs.
- Principle: Rather than generating heat, they transfer it from the outside air to the car’s interior.
- Energy Consumption: Uses significantly less energy, making it a preferable option for efficiency.
Examples include the Tesla Model 3 and Model Y adopting this technology towards the end of 2020.
Considerations for Heat Pump Efficiency
- Temperature Dependency: Heat pumps vary in performance. Some are designed to extract warmth even at lower temperatures.
- Range: At extreme cold, secondary heating systems like PTC heaters support the heat pump to maintain cabin warmth.
- Adoption: Not all modern EVs include heat pumps; for instance, the Chevrolet Bolt, Bolt EUV, and earlier Tesla Model 3 and Model Y versions were introduced without them.
Each heating technology has its merits, and your choice may depend on climate, vehicle usage, and cost considerations.
