Heat pump

[Zoidz]

At 0° F there is still heat in the air the can be concentrated via heat pump and sent into the cabin. At 0° Kelvin there is not. 0° F is 255° Kelvin - quite warm!

Agreed. The problem is that refrigerants have an optimal operating temperature/pressure curve, which is relatively narrow, especially compared to the Kelvin scale and design is always a compromise. No doubt that the design is optimized for more "normal" cold temperatures (and @crashmtb says "yo, dude, you don't know what cold is", lol) and 0F is on falling edge of the curve.

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[LeoH]

I'm in Rochester, not exactly known for balmy weather, and at no point have I even had to think about my heat. Blanket statements like "All Model 3s in Chicago had their heat fail" or "heat pumps don't work in the cold" are simply false. Tesla has too much to lose to willfully deploy HVAC systems that aren't designed to cope with the well-established temps in the northern hemisphere. Also, Teslas are becoming as common as Camrys among STEM workers. Having family with EVs is nothing special. I personally know prob 20+ people with Teslas and none have had heat issues locally (service issues on the other hand...).

The problem Tesla has faced with their heat pumps have not been from the inability to cope with cold temps, but from QC issues. Failing sensors, inlet slats getting jammed with ice, etc. They'll get it sorted eventually, as they do with most things.

Unfortunately physics disagrees. Full blown commercialized heat pumps do not work in Chicago's winters, and by law we have to install aux heat. So I am not sure what Tesla did to break the law of physics, but they need to share with the common people like myself

 

[zefram47]

Unfortunately physics disagrees. Full blown commercialized heat pumps do not work in Chicago's winters, and by law we have to install aux heat. So I am not sure what Tesla did to break the law of physics, but they need to share with the common people like myself

As others have stated, most likely scavenging waste heat from the motors and inverters.

 

[nc10]

Unfortunately physics disagrees. Full blown commercialized heat pumps do not work in Chicago's winters,

Another way to say it, you could design a heat pump that would work, but not sensibly, would require more energy than other options at those temps.

As others have stated, most likely scavenging waste heat from the motors and inverters.

Decent article linked below, I think a much much longer version of your answer, except I think not always scavenging. One option mentioned was " a bit like running your refrigerator with the door open". Sounds like Tesla has recent patents, not a lawyer but I expect Rivian would need to license if they wanted to do the same

Next time someone asks, we can say: “The system conducts thermodynamic arbitrage from finite source thermodynamic sources and has the ability to augment those finite sources “
https://insideevs.com/news/452464/tesla-model-y-heat-pump-system-details/

Would be interesting if any Model Y owners up north could comment, sounds like the Y variant heat pump system is state of the art.

 

[LeoH]

As others have stated, most likely scavenging waste heat from the motors and inverters.

Quantity has no bearing on the validity or invalidity of the concept.

In extreme conditions, the battery heat is cut off because it's barely able to keep at self at operating temperature; mind you that it takes almost 45 minutes drive to fully heat the battery before it can contribute to the heat pump. The battery heat will only kick in at operating temperature when there is full draw.

The second issue, is that it forces the motors/fans to run in Lossy mode, in other words it's trying to heat itself or as they call it compressor heat, that process itself is less efficient that traditional heat. And on top of it, that will only carry you through 5F weather without windchill factor.

So yes, it does harvest from 12 different points, but that won't carry, and at least here in Chicago, it does not carry enough heat when windchill is constantly below 0F.

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