How Do Teslas Generate Cabin Heat For Passengers? (Explained)

If you live in a cold climate where ice-coverage windshields, laden with frost are a common occurrence many months of the year, you’ll want to know about heating in Teslas before making up your mind.

The heater and defroster are champions in comparison to gas and diesel-powered vehicles.

Let’s dive deeper.

How do teslas create heat in the cabin?

Teslas generate heat by blowing air across heated coils. Think of it as an air conditioner in reverse. In summer the air flows over super-chilled coils filled with coolant, and in winter, the air blower is driving air across glowing red coils to quickly heat the interior and the windshield of the vehicle.

Can a Tesla heat up the cabin in very cold weather?

One of the magical features of electrical motors is that they run more efficiently in cold temperatures than in hot.

A Teslas’ heating system works the same way.

In a traditional vehicle, the temperature of the radiator fluid must exceed the thermostat setting, meaning the fluid has to heat to 165, 180 or 195 degrees Fahrenheit before the thermostat opens and allows the heated fluid to flow through the car’s heating coil.

This takes time, sometimes 10 or more minutes of idling before the air is heated.

In a Tesla, the heat is almost immediate, and the flowing hot air can warm the cabin of the vehicle in just a couple of minutes.

The Tesla’s battery also needs to be cooled when the summer sun is hot.

Even the most heavily frosted Tesla windshield will melt in just two or three minutes, a much faster rate than a traditional vehicle can hope for.

How much power does the heater use in a Tesla?

Depending on how you measure power consumption in your Tesla, the heater draws approximately 3 to 4% of the battery storage in raising the temperature 20 degrees Celsius.

In terms of watts consumed, the heater in a Tesla can draw up to 4,800 Watts to fully reach the desired temperature.

Heated seats also draw extra power, sometimes pulling 20 amps at 240 volts to reach the temperature setting.

How fast can a Tesla heat the cabin?

Determining how fast the temperature inside a Tesla cabin can be raised requires a little math. The heating rate in any setting is determined by a few variables.

First, how much volume must be heated? Not all cabins are the same size, so the smaller cabin will take less effort to raise the temperature, while a larger one will require more.

Think of turning the heater on in your family bathroom versus trying to raise the temperature the same amount in a three-car garage.

The second component is what the temperature is when you start the heater, and what your target temperature is.

The colder the start, and the higher the goal, the longer heating will take.

The third component is how fast the blower can move air.

Setting the blower at a lower level takes more time to increase the heat, while a faster setting moves more air over the same amount of time.

The good news about a Tesla is that the temperature begins to raise almost immediately. Once the desired temperature is set the electric coil kick into action and the air flowing over them is heated automatically.

The average process for raising the interior of a vehicle from 40 to 70 degrees Fahrenheit is around two minutes. That’s very fast in comparison with any other traditionally powered vehicle.

How long can a Tesla run the heater when parked?

This depends on how much battery charge remains when you park the Tesla.

A parked Tesla with the heater on will typically use 2 to 3 percent of the battery per hour.

Check also our article about how long a Tesla can stay warm in city traffic (queues).

That means a fully charged Tesla will keep the car’s interior warm for 30 to 50 hours depending on the heat settings, the battery charge remaining and the temperature outside.

Colder external temperatures will result in draining the battery faster, resulting in Tesla batteries being affected by cold temperatures.

Just maintaining a temperature a few degrees above the outside temperature will not drain the battery as quickly.

We also find overheating checks in Teslas.

Does the motor generate heat for the car?

With traditional fuel-powered vehicles, the heat to warm up the interior of the car comes from the cooling fluid as it heats up while cooling the side effects of internal combustion.

A Tesla running solely on electricity doesn’t generate heat that way.

But motion will generate heat and new models use that concept with a heat pump that will transfer the heat produced by the Tesla as the electric motor runs into internal heating for the occupants.

A heat pump is more efficient in terms of battery use since it just transfers the heat from one area of the car to another.

Tesla models that relied entirely on air flowing overheated coils to warm the heater and defroster drained batteries as the coils were engaged.

Since there is no additional energy demand with the car already in motion, a heat pump is a more efficient way to run a heater or defroster to keep the cabin warm, and the windows free of frost and ice.

How do other electric cars generate heat?

The two primary methods of generating cabin heat in an electric vehicle are either:

  1. a heat pump or
  2. resistance heaters.

We have a full article here on how AC and heating work in electric cars.

A heat pump is just a method of moving heat from one area of a vehicle to another. Electric cars are much more efficient in energy terms than gasoline or diesel-powered vehicles which produce tremendous amounts of heat as they physically burn fuel.

An electric vehicle also produces heat.

The tires generate heat in contact with the road, the motor generates heat as it runs, more heat is generated when the motor is under load as in going up a long hill or pulling a heavy trailer, and it generates less with a single occupant versus being fully loaded with passengers.

All this heat can be moved via a heat pump from the engine compartment to the interior of the vehicle, or in extremely cold conditions to the battery storage area.

An electric motor works best in colder conditions, but batteries don’t do as well when they’re cold. A warmer battery is more efficient than a cold one.

Think of starting a traditional petroleum-powered vehicle on a warm afternoon versus the cold cranking, clicking sound your battery can generate when it’s well below zero degrees.

That’s the magic of a heat pump.

Resistant heating in vehicles has been around for a long time.

Long haul truckers often use 12-volt heaters with fans attached plugged directly into their semi-truck wiring to keep the windshield free of ice in heavy winter conditions.

Owners who operated Volkswagen Beetles and the now-defunct Chevrolet Corvair used 12-volt heaters and defrosters since the air-cooled, rear-mounted engines didn’t produce any hot cooling liquid to run through a heater core and then into the vehicle.

Electric vehicles share the same limitations that air-cooled engines do in cold, winter conditions.

need an alternative source of heat since there is not a heater core using anti-freeze flowing through the engine to heat it.

Final Thoughts

A Tesla can operate in any climate or temperature conditions that a traditional fuel-powered vehicle can.

The differences in the fuel source and the cooling properties necessary for gasoline and diesel-powered engines make heating the interior of a car or truck a simpler process than an electric-powered vehicle such as a Tesla.

That doesn’t mean the alternative method of heating the cabin is less efficient.

In many ways, using resistant, battery-powered electric heating and operating a heat pump are better solutions that running a hot liquid through rubber hoses throughout a vehicle as is done with traditional internal combustion engines.

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