? Impact of a heat pump on R1 efficiency?

[R1 EVY]

Hey people way smarter than me,

What effect would a heat pump do on efficiency? I'm currently getting 2.0-2.2 in all-purpose mode on 21's and I'm just curious how much that would improve?

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[Zoidz]

Around 5% to maybe 10% maximum improvement when the heat pump is in use in cold weather, so maybe 0.1 - 0.2 better. And the colder it gets, the less efficient it is so the return is diminished.

 

[SeaGeo]

It really depends o how fast you're traveling. At highway speeds, especially with a warm battery, I suspect the impact will be marginal. Overnight camping? It should cut down usage quite a bit.

 

[usofrob]

The above answers are what I was expecting as well. Even if the heat pump uses half the energy, it's still not using that much energy in the steady state.

I wonder if the effect is greater for shorter trips. The initial heating of the cabin and battery uses a lot of energy. This would mean as a total vehicle percentage, the 50% improvement of the heating could have a larger impact.

 

[Electrified Outdoors]

On my Tesla the heat pump was great until it got below 20° F. Below that it couldn't keep up and efficiency went down the tubes.

I honestly think the Rivian is pretty darn efficient for not having a heat pump. A 5-10% gain is huge in the EV world though.

 

[R1Tom]

I wish the heat pump would be optional. It adds complexity and cost and for some people the benefit is not significant.

 

[R1 EVY]

On my Tesla the heat pump was great until it got below 20° F. Below that it couldn't keep up and efficiency went down the tubes.

I honestly think the Rivian is pretty darn efficient for not having a heat pump. A 5-10% gain is huge in the EV world though.

That makes sense. Thanks for that data point.

 

[Eric9610]

I had a tesla with Hp technology and I much prefer traditional system for marginal improvement. It took for ever to cool or heat the car with the Tesla and it never felt like it got to temp properly. I have been in other cars with HP technology and it’s the same story. I live in a warmer climate so the real need for heat is low. With the ability to warm pack from home power for pre conditioning makes a big difference preventing the need for a HP in my mind.

 

[BigSkies]

I’m no engineer, but the little I know is that these EV heat management systems are much more complicated than people give them credit for.

I think the real answer is much more nuanced than yes/no on a heat pump.

People that have driven both Rivian’s and Ford’s have reported that Rivian’s lose much less power in the cold than Ford’s (at least I remember reading that on here). So Rivian has already implemented some level of heat/temp management optimization even without a heat pump.

Maybe it has to do with how Rivian sources heat from the motors.

Based on my experience with residential heat pumps, my guesstimate is that it would be roughly halfway between the efficiency of cold weather vs warm weather driving. So if you’re getting 2.0 in the winter and 2.2 in the summer, you could maybe expect 2.1 in the winter. However, the real world impact will be lower, as heat pump efficiency/effectiveness/functionality drops precipitously at lower temperatures. Particularly below freezing.

So yes, a heat pump makes a difference and is a worth developing. Is it something worth getting really excited about? Not really.

 

[Jabbahop]

Here is a video test of bmw i3 with and without heatpump. Basically small gain from heat pump version because driving takes so much more energy than heating.

It will be interesting to see with the Rivian.

 

[R1Tom]

Here is a video test of bmw i3 with and without heatpump. Basically small gain from heat pump version because driving takes so much more energy than heating.

It will be interesting to see with the Rivian.

Everytime I see one of those I think it looks like a Smart Forfour on 4 temporary spares.

 

[Zoidz]

A heat pump in a EV provides a small efficiency value but huge marketing hype value.

 

[Jabbahop]

Everytime I see one of those I think it looks like a Smart Forfour on 4 temporary spares.

Looks are odd but love ours for round town stuff. 5.1 miles/kwh for the past 3 months. Parking and turning radius is incredible plus plastic body panels so no PDR ;-)

 

[R1 EVY]

I had a tesla with Hp technology and I much prefer traditional system for marginal improvement. It took for ever to cool or heat the car with the Tesla and it never felt like it got to temp properly. I have been in other cars with HP technology and it’s the same story. I live in a warmer climate so the real need for heat is low. With the ability to warm pack from home power for pre conditioning makes a big difference preventing the need for a HP in my mind.

I'm in Wisconsin, so the need is real

 

[R1 EVY]

I’m no engineer, but the little I know is that these EV heat management systems are much more complicated than people give them credit for.

I think the real answer is much more nuanced than yes/no on a heat pump.

People that have driven both Rivian’s and Ford’s have reported that Rivian’s lose much less power in the cold than Ford’s (at least I remember reading that on here). So Rivian has already implemented some level of heat/temp management optimization even without a heat pump.

Maybe it has to do with how Rivian sources heat from the motors.

Based on my experience with residential heat pumps, my guesstimate is that it would be roughly halfway between the efficiency of cold weather vs warm weather driving. So if you’re getting 2.0 in the winter and 2.2 in the summer, you could maybe expect 2.1 in the winter. However, the real world impact will be lower, as heat pump efficiency/effectiveness/functionality drops precipitously at lower temperatures. Particularly below freezing.

So yes, a heat pump makes a difference and is a worth developing. Is it something worth getting really excited about? Not really.

I'm guessing my summer efficiency will be around 2.4-2.5. So the average would be 2.3 m/kWh. I would really appreciate that in the winter.

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