Has anyone tested ‘24 heat pump?

[Jake24]

I'm not sure what your response was to in my post.

neither am I

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[Nklem]

I'm a firm believer in heat pump technology but I'm skeptical they make much difference in an EV.

Many, maybe most, AC units in the SW desert use heat pump technology. With the development of multi-stage pumps that technology is increasingly utilized in more moderate climates, as well (but it isn't cheap to install or repair, which has implications for its use in vehicles). Many pool owners around the country use heat pumps to heat their pools (but not spas, and the reasoning for that will become more clear as I explain). Many here will also be familiar with the increased use of heat pumps in things like water heaters, for example.

The "problem" with all those implementations is they sit in one place and take a while to warm up. The whole benefit of a heat pump is the well-known principle that operating a pump at its most efficient point can result in enormous energy savings compared to a standard pump or AC compressor--but those energy savings are often realized through operating the heat pump in low and slow conditions.

What that means is that you heat/cool a house and then maintain it there (with lots of insulation), you warm the water heater's water up and then maintain it there (with lots of insulation), you warm the pool water up and then maintain it there (with a pool cover--or, in other words, insulation). Anytime you need a burst of energy the heat pump's efficiency takes a nosedive. Water heaters are hybrid so you can use a heating element when the water use outstrips the pump's efficiency. Homes either have supplemental heating or the occupants have to use personal insulation--and the packaged units have emergency resistive heat strips just in case. A pool heat pump simply can't keep up without a cover and worse than worthless in a high demand use-case like a spa.

What does all this have to do with an EV?

Well, I would argue that EV driving approximates high-use, high-demand use cases. When you get in, the car is generally cold (or hot) and you want to change that very quickly for occupants' comfort. *Most* driving patterns are local/short trips and EVs in particular don't do well with long trips because you have to stop and charge every couple hours.

So where does that leave us? If you can adjust the cabin before you leave then the heat pump can probably efficiently maintain it. If you're driving to the grocery store it probably doesn't matter, though--you might as well just use the seats, wheel, and could even just put the blower on full blast since you'll come right back home and can plug it in. If you're going for a two hour drive it'll probably help eke out some savings but, again, only if you start out with the cabin where you want it. Maybe if you're going for a really long trip it starts to make more sense but now you're dealing with losses through the truck's insulation (or lack of).

So all in all we end up with percentages of differences rather than night and day, which is why every major manufacturer who has implemented heat pump technology has either faced a lawsuit or recall from their customers. Someone said they did wonders for the model 3 in this thread but my read of the issue is that customers have had to suffer recalls, high cost repairs, and unexpected technological issues...for about a 10% increase in range (and again this isn't across the board as it could only realistically reveal itself during longer trips). Once they're standard features the choice won't be your problem to make anymore but currently it's hard to justify spending more for a specification that really only pans out on paper, imo. In short, the juice probably isn't worth the squeeze.

Hyundai has the leg up on EV heating. The Ioniq 5 has an 100% efficient variable power 7 kW resistive air duct heater for backup and super cold weather in the cabin. -15 to 70F in under 10 minutes. They also have a "Refrigerant to air" coil for the heat pump next to the duct heater. NO FLUID TO HEAT PUMP OR FLUID TO PTC. It is super efficient and fast. My Mach E ER with 88 kWh battery had a winter range of 175-180 miles normal winter and 130-138 at -5F. My Ioniq 5 with 74 kWh had 200 miles of winter or better and at -15F still had 155 miles. They have a dedicated 4.5 kW fluid PTC with the heat pump HX for battery cooling and heating totally separate from the HVAC system. Frankly down to -15F my battery never heated. The only battery heating was when a DCFC was scheduled below freezing and before getting to the charger. 150 kWH charging at 5F was amazing. the maximum battery capacity loss due to ambient temps was under 10%. Anyway the Lightning (2023) has the same system as the Mach E and the heat pump, from what I hear, the 2024, is a denso system ( I am sure similar to the Denso Toyota/Subaru BZ4X HP system).

I am anxious to hear if it does anything for the 2024's. I had a Solterra and it's wintertime efficiency was right there with the Mach E and ultimately failed which is why I do not have it any longer. The Hyundai diagram is below.

I am excited to see my 120 Mile winter range in another 4-6 months. You cannot beat the lightning ride and drivetrain!

 

[GoodSam]

24 SR/ER range is 240/320, so only a boost on the SR from the 22 230/320?

 

[mrau]

24 SR/ER range is 240/320, so only a boost on the SR from the 22 230/320?

Don't believe the heat pump will increase the range ratings.

However, the heat pump should reduce range loss in colder weather.

 

[potato]

"The whole benefit of a heat pump is to use electricity to move existing heat from one place to another, rather than converting that electricity to heat directly."

That benefit is based on the principle I wrote: the efficiency gains are realized through using the "electricity" to power a variable speed motor at a lower speed.

I would argue that the *biggest* efficiency gains are realized by using a refrigeration system (compressor, condenser, orifice, evaporator) vs a resistive heater. The existence of that refrigeration system is "heat pump technology" in an automotive context. The way I read it anyway. I have a feeling you are referring to something fancier when you say "heat pump technology".

Anyway we completely agree on the conclusion. I also think the benefit of heat pumps in an EV are pretty situational. The outside temperature has to be within the range where the system operates efficiently, and as you say, unless you have it running all the time so it's in a steady state, the heat pump system itself probably can't be all that efficient. Maybe if your electricity cost was really high you would care. But it seems to me you might gain 2 or 3 kW over a resistive heater... in an inefficient vehicle like the Lightning which takes 40 kW just to get down the highway, that's not a night and day difference.

If in a real crunch where we need every bit of range, most of us would turn off the cabin heating anyway, heat pump or no heat pump, and just go with the seat and steering wheel heaters.

 

[Newton]

I'm about to take a 4000 mile trip in my 23 SR. You say you've not really had an issue traveling in the SR? Range for me isn't an issue in the winter, but I do more traveling in the Summer when temps are up.

No, it might be different in other parts of the country. We stop more for breaks than we do to charge

 

[00SVT]

24 SR/ER range is 240/320, so only a boost on the SR from the 22 230/320?

That’s max range. The difference may be more apparent if they noted max range at different temperatures like 32 degrees, 70 degrees, and 95 degrees.

 

[Nklem]

24 SR/ER range is 240/320, so only a boost on the SR from the 22 230/320?

The 23 SR/ER was rated at 240/320

 

[Ferroxide]

Jelly! beautiful!

 

[MADequipment]

I bought a 2024 Lariat.

Will post updates when it's wintertime. So far in the summer I've logged 650 miles since purchase. 40% (at 40 mph) and 60% (65 mph). Lifetime average is 2.6 mi/kWh. I'm located in Minnesota for reference. This is a place where hot is very humid and cold is sub zero.

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