A/C and Heater Energy Comparison

[NC-Rivian]

Now that the temperatures are getting cooler, I was wondering which system uses more energy: A/C in summer or heater in winter?

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[Dark-Fx]

Heater. By far.

 

[Rousie13]

The heater definitely sucks the juice.

You learn to turn the heat down and seat/steering wheel heaters up in an EV to keep the range up. If you don’t care about efficiency/range, then crank the heat up.

 

[ravian]

Is the heater “heat pump” based?

 

[godfodder0901]

Is the heater “heat pump” based?

No.

 

[Dark-Fx]

Is the heater “heat pump” based?

No but Rivian has a couple patents on how they plan on implementing it. Polestar shipped the 2 for the first model year without a heat pump and added it as an option for year 2 as part of a package. I'm curious how Rivian will end up implementing it, if it'll just be a random switchover time or if they'll charge extra for it.

 

[Rousie13]

For Volvo the heat pump is included in the top trim, but only included in a package for the lower trim. If you don’t add the package, then no heat pump.

 

[NY_Rob]

FWIW... the Bolt heater (similar to the type used by Rivian) pulled 7,500 watts at full power. I couldn't imagine Rivian's heater pulling less than the Bolt system.

 

[Dark-Fx]

FWIW... the Bolt heater (similar to the type used by Rivian) pulled 7,500 watts at full power. I couldn't imagine Rivian's heater pulling less than the Bolt system.

Hummer EV has a heat pump but also a secondary resistive heater. The display would show 12-13kW being drawn just sitting still if you flipped the heat on when the truck was cold.

 

[CharonPDX]

Depends on how hot/cold you're talking about. When you think about it, you're moving heat around. The temperature differential is a large component of that.

If your comfort temperature is 70 F, and the outside temp is 90F, you're only changing it 20 degrees.

If the outside temp is 30 F, now you're changing it 40 degrees.

Then add in the fact that an air conditioner is a form of heat pump (it moves heat from inside the cabin to outside - sadly it isn't a reversible heat pump that can also heat the cabin,) which is more efficient than simply generating heat - so even if the "heat the cabin" temperature change *were* only 20 degrees, the AC would still be more efficient than the heating system (which uses a resistive heater - basically just apply electricity to a wire until it gets hot, then blow air over it.)

 

[Andystroh]

Hummer EV has a heat pump but also a secondary resistive heater. The display would show 12-13kW being drawn just sitting still if you flipped the heat on when the truck was cold.

Are these numbers like full output, or what its set to while driving comfortably? I guess it will probably reduce as the temperature increases, but I would notice about 1 kW to maintain a comfortable temperature while at stoplights in my ID4 (which only displayed total output so I could only read while stopped).

We don't have access to these numbers in the Rivian yet do we? Would be interesting to measure as the temps drop...

 

[Dark-Fx]

Are these numbers like full output, or what its set to while driving comfortably? I guess it will probably reduce as the temperature increases, but I would notice about 1 kW to maintain a comfortable temperature while at stoplights in my ID4 (which only displayed total output so I could only read while stopped).

We don't have access to these numbers in the Rivian yet do we? Would be interesting to measure as the temps drop...

First starting up, unplugged, with everything cold. Starting with a very preconditioned vehicle, it used 8kWh (4% of the total usage) off the battery to drive 242.8 miles at 70 mph in below freezing weather.

I think through the Rivian RIDE menu the consumption numbers might have been available but I didn't ever look through it.

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