Heatpump is the biggest upgrade in Gen 2, imo

[Dark-Fx]

Depending on how it is designed it can also be set up to share heat between other components (cabin, radiators, battery and motors). This last distinction is completely up to to the engineers (or rather finance) and is not a package deal when you see that an EV added a heat pump.

You can also do this with traditional AC and no "heat pump". It's all about the valving involved.

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[TripleB]

Heat pumps are more efficient.

 

[R1Tom]

I am hoping the bot replies to these latest posts.....it should be entertaining!

 

[Eric9610]

I work in the industry a HP is only more efficient than resistant heating as stated earlier in the posts. This is a fact. For cooling it is literally the same as an AC unit.

What I have only seen 1 person post and it is the most important factor in EV efficiency increase is the implementation of the refrigerant routing for the pack. Tesla uses an 8-way valve that moves to maximize the HP system. Without this its marginally a efficiency increase, and I would argue an inferior one for heating. As HP units struggle to get things warmed in cold climates. Google all the tesla complaints from owners.

 

[Autolycus]

This thread is just painful to read: An AC system is a heat-pump, a heat-pump is also a heat-pump, a refrigerator is also a heat-pump.

Since the thread is already largely derailed, I'm going to pick a very small nit. MOST refrigerators use a uni-directional heat pump, but some do not. Some small refrigerators -- think the ones that are for a few bottles or even some "dorm" size -- use Peltier cooling systems rather than compressor-based cooling systems.

In general, this thread has provided a lot of entertainment, especially the comment about the avatar being an AI-generated image with the word Rivian but a picture of a not-Rivian vehicle.

 

[portdirect]

Since the thread is already largely derailed, I'm going to pick a very small nit. MOST refrigerators use a uni-directional heat pump, but some do not. Some small refrigerators -- think the ones that are for a few bottles or even some "dorm" size -- use Peltier cooling systems rather than compressor-based cooling systems.

In general, this thread has provided a lot of entertainment, especially the comment about the avatar being an AI-generated image with the word Rivian but a picture of a not-Rivian vehicle.

I hereby accept your nit with grace sir.

 

[Autolycus]

Heat pumps are more efficient in some situations, none of which involve hot summer days.

FIFY.

 

[SoCal Rob]

Since the thread is already largely derailed, I'm going to pick a very small nit. MOST refrigerators use a uni-directional heat pump, but some do not. Some small refrigerators -- think the ones that are for a few bottles or even some "dorm" size -- use Peltier cooling systems rather than compressor-based cooling systems.

In general, this thread has provided a lot of entertainment, especially the comment about the avatar being an AI-generated image with the word Rivian but a picture of a not-Rivian vehicle.

If you want another off-topic exception, some refrigerators use an entirely different process: absorption refrigeration. This is an older technology which doesn’t require electricity at all. These are pretty common in campers and motor homes. We have one in our camper which uses either a propane-fueled flame or 120V electric resistance element as the heat source to drive the cooling process. I don’t think they’re especially quick or efficient, otherwise car manufacturers would have used this setup for cooling already. I hope.

https://en.m.wikipedia.org/wiki/Absorption_refrigerator

 

[R1SFamilyGuy]

The punctuation is too perfect as well..

This is definitely a bot or a human just putting everything into ChatGPT. These responses are amazingly simplistic and actually full of errors....

 

[SoCal Rob]

The difference between just an AC unit and a heat pump is a heat pump has a refrigerant reversing valve. ( Tesla actually had a very sophisticated octo valve that had 8 possible positions).

Just to be clear, it seems the very clever Octovalve only routs the coolant/antifreeze liquid and not the refrigerant itself.

From https://www.emobility-engineering.com/tesla-octovalve/
“Water-glycol coolant flow to and from all these components is controlled by the Octovalve, which Steuben describes as a small, unassuming part that looks like a cylinder lying horizontally on its base.

It is a rotary valve, with eight ports that mate to matching ones on the water-glycol manifold; it has five internal valve positions to direct flow through all the coolant loops.”

This article also includes the part which may interest people who are wondering about the cooling part of this heat pump system. It doesn’t do anything differently than conventional A/C for cooling when the entire vehicle is warmer than desired: “A coolant radiator and a refrigerant condenser are in the conventional location at the front of the vehicle and reject heat to the atmosphere when the whole system is at high temperature.”

 

[Chrisy]

Man, this thread is a fantastic read (minus the bot).
This happens when a bunch of engineers get together in one place

 

[R1Tom]

Man, this thread is a fantastic read (minus the bot).
This happens when a bunch of engineers get together in one place

Spot on! Heat pumps are definitely a good thing, but alot is overstated. And the word itself that the industry adopted..."Heat pump"....is even misleading to many.

 

[Zoidz]

I'll throw a few comments into the dogpile:
- As stated by others, AC is fundamentally a heat pump.

- When cooling on a hot day, it has to dump the recovered heat somewhere, which is almost always going to be the atmosphere via an air exchange condensor coil. On hot days, the battery, motors, electronics all may/will need cooling. I seriously doubt they will dump heat INTO the battery on a hot day!

- The cooling will generally work better on a hot day when the vehicle is moving, since there is increased air flow through the condensor coil which improves heat extraction from the refrigerant. You can experience this in some ICE vehicles.

- Most new vehicles use an earth friendly refrigerant R1234YF. Various studies show this refrigerant has a 4% to 15% lower COP (Coefficient of Performance) than the old standby R134A found in older cars. That means the refrigeration system in new cars has to run longer/work harder as compared to older vehicle AC systems to provide the same cooling.

- There is one potential efficiency gain with a heat pump system when used for AC. Traditional Air Conditioner compressors typically run at one speed (or in cars, whatever the ICE RPMs are) regardless of the cooling demand. They may have a clutch (cars) or unloading valve (commercial/industrial) to try to save energy. New designs, such as Rivian's current air compressor, as well as all newer heat pumps, run at a variable speed based on cooling demand, which saves electricity.

Regardless, It's all better than this:

 

[Zoidz]

Just to be clear, it seems the very clever Octovalve only routs the coolant/antifreeze liquid and not the refrigerant itself.

From https://www.emobility-engineering.com/tesla-octovalve/
“Water-glycol coolant flow to and from all these components is controlled by the Octovalve, which Steuben describes as a small, unassuming part that looks like a cylinder lying horizontally on its base.

It is a rotary valve, with eight ports that mate to matching ones on the water-glycol manifold; it has five internal valve positions to direct flow through all the coolant loops.”

This article also includes the part which may interest people who are wondering about the cooling part of this heat pump system. It doesn’t do anything differently than conventional A/C for cooling when the entire vehicle is warmer than desired: “A coolant radiator and a refrigerant condenser are in the conventional location at the front of the vehicle and reject heat to the atmosphere when the whole system is at high temperature.”

Yes, the octovalve has 8 ports with 5 positions. It's a creative solution to solving a problem, but it's far from magic. If someone has a water softener in their home, you have a rotary valve that conceptually works just like the octovalve.

 

[Autolycus]

Yes, the octovalve has 8 ports with 5 positions. It's a creative solution to solving a problem, but it's far from magic. If someone has a water softener in their home, you have a rotary valve that conceptually works just like the octovalve.

Yeah, yeah, and if you have a lighter and flatulate you also have a rocket engine that conceptually works like Merlin. Don't act like Elon didn't revolutionize the world.

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