Reversible heat pump in newer Model S?

[Galinette]

I know that my pre raven Model S heats the cabin (and battery?) with a 6kW resistor (you see the power consumption clearly with the Remote S app when turning heat on), and AFAIK the Model 3 uses a reversible heat pump for both heating and cooling, potentially dividing the power use by 3 for heating.
Has this been updated in the Raven refresh? If not this is probably the last big advantage of model 3 (along maybe charge speed...)

 

[mtndrew1]

I know that my pre raven Model S heats the cabin (and battery?) with a 6kW resistor (you see the power consumption clearly with the Remote S app when turning heat on), and AFAIK the Model 3 uses a reversible heat pump for both heating and cooling, potentially dividing the power use by 3 for heating.
Has this been updated in the Raven refresh? If not this is probably the last big advantage of model 3 (along maybe charge speed...)

No Tesla models for sale now or in the past have a heat pump. All are resistance heaters.

 

[SSedan]

My primary home heat is Fujitsu air source heat pumps. The way they frost up in humid weather would be a major hurdle in a car. In a house the system can reverse for a few minutes blow some cold air in the house to defrost the coil. That wont fly in a car with the small cabin.
Car is a LOT more likely to be in a mist environment which would cause a lot of frosting.

Once the temps fall to -15F I end up supplementing my home heat with the old baseboard electric system as the heat pumps don't keep up.

I know a lot of folks think freezing is cold, there are a lot of us that shovel the driveway in short sleeves if it is right around freezing because we are accustomed to much colder. Car has to be capable of handling much colder. Then you get into having to have a resistance heat system as well and integrate it. The heat pump only working well if the heating need is fairly modest.

 

[Galinette]

No Tesla models for sale now or in the past have a heat pump. All are resistance heaters.

You are right, I had the wrong information.
Most other EVs have, though... Come on, Tesla!
Things may change when they integrate HVAC consumption in EPA tests.

 

[Battpower]

My cheap Renault Zoe's have all had blended braking and heatpumps since the first one several years ago. In typical UK winters no problems. I also have air-source heat pump at my house and yes, it suffers from frosting up. However, from a user perspective I can say that my Model S Raven is certainly no better than the Zoe with regards to cabin fogging / humidity, and while my feet end up freezing in the Tesla, I never have an issue in the Renault.

One pedal driving kind of does away with need for blended braking, but does allow a car to be driven exactly like a regular ICE auto.

I would gladly trade farts and ping-pong AP for decent energy efficient heating.

 

[Naekuh]

i honestly dont think the car has an AC powerful/efficient enough to run a reverse pump.

A reverse pump works better as others stated when the outside temp to inside temp has a moderately delta.
In essence instead of cooling the condenser coils, you are trying to heat them up, and when your outside temps are low, well, you can see how efficient that can be.

This is why i always thought cars ran on either resistors, or heater coils, which basically recycled the coolant in the engine on ICE cars as that coolant is always at a high temp and can benefit from the additional cooling.

The reason why its more efficient at homes is because you got a condenser which is typically as big as the entire front end of your model S, hence more surface area, and can take a larger swing even in colder temps.

 

[SSedan]

Can't compare the size of a home heat pump vs car because of the size of the space being heated.
Home is thousands of cubic feet Model S is 95cubic feet.
Bet the defrost cycle would require a refrigerant heater.

How does the Zoe heat pump function in sub-zero Fahrenheit temps?

Chicago USA has comparable winter temps to Oslo, maybe the heat pump is great to 0F but cars that are to be marketed heavily in colder places are just poor candidates.

 

[mtndrew1]

i honestly dont think the car has an AC powerful/efficient enough to run a reverse pump.

A reverse pump works better as others stated when the outside temp to inside temp has a moderately delta.
In essence instead of cooling the condenser coils, you are trying to heat them up, and when your outside temps are low, well, you can see how efficient that can be.

This is why i always thought cars ran on either resistors, or heater coils, which basically recycled the coolant in the engine on ICE cars as that coolant is always at a high temp and can benefit from the additional cooling.

The reason why its more efficient at homes is because you got a condenser which is typically as big as the entire front end of your model S, hence more surface area, and can take a larger swing even in colder temps.

My Kia Soul EV had a heat pump and it was considerably more efficient than the Model 3’s resistive element between 35 and 65 degrees Fahrenheit. It generally pulled 1.5 kW for a brief period to bring the cabin up to temp and then cycled on and off at 0.5 kW.

 

[Battpower]

My Kia Soul EV had a heat pump and it was considerably more efficient than the Model 3’s resistive element between 35 and 65 degrees Fahrenheit. It generally pulled 1.5 kW for a brief period to bring the cabin up to temp and then cycled on and off at 0.5 kW.

Very similar to the Zoe. On shore power the cabin pre-heat runs the heat pump at 2.5 kw (ish) iirc and heats the cabin very quickly with ambient temps down to -7 calcius. With lower ambient you are bound to loose the benefits, but I have been happy with performance.

It does mean of course you have to keep the ac / heat pump tuned and in good shape, but you probably want to do that for the ac anyway.

 

[SSedan]

-7C isn't even cold yet for a lot of us.

Maybe I haven't been explicit enough on stating this.
I don't believe a heat pump would perform well enough everywhere.
I live near Green Bay Wisconsin I have seen actual temp of -26F (-32C)at my house and driven the Model S at -23F done a 180mile stretch between superchargers at 3F. While it would stand to reason a heat pump would help most on those long drives what impact does defrosting the coil have? Short trips this would be less of a thing if the car can then take the time to warm and defrost while stationary.

Guessing warming the coil at 70mph to defrost it might be challenging, compared to a car designed for city driving.

No auto mfg. is perfect but I think we need to trust the engineers had a reason for sticking with resistance heat. Maybe the reason is just that they were still going to need resistance heat anyway so why have two systems. Not saying it has to be a technical reason. I just think too many are blind to the possibility or IMO probably it is a technical reason.

 

[Battpower]

-7C isn't even cold yet for a lot of us.

Maybe I haven't been explicit enough on stating this.
I don't believe a heat pump would perform well enough everywhere.
I live near Green Bay Wisconsin I have seen actual temp of -26F (-32C)at my house and driven the Model S at -23F done a 180mile stretch between superchargers at 3F. While it would stand to reason a heat pump would help most on those long drives what impact does defrosting the coil have? Short trips this would be less of a thing if the car can then take the time to warm and defrost while stationary.

Guessing warming the coil at 70mph to defrost it might be challenging, compared to a car designed for city driving.

No auto mfg. is perfect but I think we need to trust the engineers had a reason for sticking with resistance heat. Maybe the reason is just that they were still going to need resistance heat anyway so why have two systems. Not saying it has to be a technical reason. I just think too many are blind to the possibility or IMO probably it is a technical reason.

I'm sure there are many reasons resistive heat could be better. Simpler, less weight, no re-gassing, more consistent and predictable performance, works at far lower temperatures, less expensive .....

I can only say as I find and that is for me, I really appreciate the efficiency of the heat pump in -10 C and above and also with a 40kwh battery.

In my Model S I hardly care how it heats as long as I see 300 + miles when I need it.

 

[SSedan]

The resistance heat is a BIG hit on short hops, but in my experience not that bad on long trips. heating the cabin is the problem, not keeping it warm.

 

[Battpower]

The resistance heat is a BIG hit on short hops, but in my experience not that bad on long trips. heating the cabin is the problem, not keeping it warm.

I've found the same. And since I use the Zoe for many shorter journeys (under 50 miles and typically 10-15) with a small battery capacity, the heat pump really helps.

On the Raven S LR it seems to heat quite enthusiastically when I first get in the car, irrespective of heat settings, but then cut back to a just about tollerable degree of heat. Certaiy no noticeable effect on range on longer trips over 50 miles.