Model Y heating - slow

[2101Guy]

You'll be surprised how quickly the Y cabin heats up in most temps (above 15F). Mine is in an insulated garage, so most mornings is about 40-45F in my garage. It takes about 6 minutes to heat my cabin to 66F. If you like it warmer, obviously it'll take a little longer but I find the Y heats up the interior faster than my previous gas vehicles.

this is my experience as well. In facts, in about 6 mins im from 45 to about 70

 

[pkitch]

Highly unlikely due to the lower power draw with the HVAC on w/o pre-conditioning. If there was additional heating elements, the power draw at idle would be much higher. I'm only seeing 500-600 watts at idle with the heater on and no pre-conditioning (I've only done this twice for other tests). If the car was immediately blowing warm air with resistive heating, it'd be drawing well over 2000 watts.

Here's a graph showing how fast the stator motors warm up and why resistive heating isn't needed. Within 2 minutes the front motor is at 150F, the rear motor is at 130F (blue and red line). At 5 minutes, 160F & 130F respectively.. The red line is what I find interesting. This is the battery inlet temperature, which is the temp of the refrigerant prior to entering the battery pack. Between 1 minute and 2 minutes is where there's some non-linear activity. This is where, I believe, the heat is pulled from the refrigerant and directed to heat the cabin instead of the battery, hence the dramatic drop in the battery inlet temp. After 2 minutes, it resumes the rise in temp once the cabin reaches the target temperature.

View attachment 626919

Thanks for the detail, really good information thanks for taking the time to post it. I am very impressed that this is achieved without a heating element.

Do you know how the heat is built up/generated in the motor, is it just friction from spinning the motors? Is there a clutch mechanism to detach drive or is there some other way? I imagine the coils would generate heat if the rotor insider the motor was prevented from spinning?

 

[pt19713]

Thanks for the detail, really good information thanks for taking the time to post it. I am very impressed that this is achieved without a heating element.

Do you know how the heat is built up/generated in the motor, is it just friction from spinning the motors? Is there a clutch mechanism to detach drive or is there some other way? I imagine the coils would generate heat if the rotor insider the motor was prevented from spinning?

Tesla has designed the 3 and Y motors to create a non-motive power waveform to produce heat in the stator motor.
It's pretty amazing how fast the motors warm up, as shown in my previous graph.

What I didn't post (since it didn't apply to the previous questions) was the graph of the motor and battery pack temps after the preconditioning. Here's the graph showing the various points of data for a 33 minute drive.

Weather conditions were pretty bad, 26F, roads were icy with packed snow, and further into the drive it got a little better with mostly wet and slushy roads. Here are the stats from the drive:
* Front Stator motor started at 190F, finished at 77F
* Rear Stator Motor started at 162F, finished at 95F
* Battery inlet temp started at 75F, finished at 61F
* Cell Temp Mid (battery pack) started at 69F, finished at 67F
* Car set to Chill mode, low brake regen. Topography fairly flat.

The car was able to maintain the battery pack temp for about 10 minutes since the front and rear motors (blue and pink line) were above 100F during that duration. You can also see the battery inlet temp (temp of the refrigerant prior to going through the battery pack) dipping at around the 10 minute mark. This was when I turned on the heat for a little bit, so the system pulled the heat that was originally directed to the battery to go into the cabin. Visually you can see on the red line when I did this.

The car has a lot of amazing tech going on in the background. Most owners will never realize what's going on and take the design and tech for granted.

 

[mark95476]

My MY starts blowing warm air within ~15s.

Have you tried hitting the front defrost twice so it's on high/red? It consumes HUGE energy! I was charging last night (6 kW), hit the defrost to clear the fog on my windows and charge time estimates went from ~4 hours climbed steadily to >>12 hours within a minute. Turing it off dropped the estimate back down.

(Aside: We don't really have cold weather in the Bay Area, CA--I think the car said it was 71deg yesterday and today is shorts and t-shirt weather so it's probably the same ).

Tesla has designed the 3 and Y motors to create a non-motive power waveform to produce heat in the stator motor.
It's pretty amazing how fast the motors warm up, as shown in my previous graph.

What I didn't post (since it didn't apply to the previous questions) was the graph of the motor and battery pack temps after the preconditioning. Here's the graph showing the various points of data for a 33 minute drive.

Weather conditions were pretty bad, 26F, roads were icy with packed snow, and further into the drive it got a little better with mostly wet and slushy roads. Here are the stats from the drive:
* Front Stator motor started at 190F, finished at 77F
* Rear Stator Motor started at 162F, finished at 95F
* Battery inlet temp started at 75F, finished at 61F
* Cell Temp Mid (battery pack) started at 69F, finished at 67F
* Car set to Chill mode, low brake regen. Topography fairly flat.

The car was able to maintain the battery pack temp for about 10 minutes since the front and rear motors (blue and pink line) were above 100F during that duration. You can also see the battery inlet temp (temp of the refrigerant prior to going through the battery pack) dipping at around the 10 minute mark. This was when I turned on the heat for a little bit, so the system pulled the heat that was originally directed to the battery to go into the cabin. Visually you can see on the red line when I did this.

The car has a lot of amazing tech going on in the background. Most owners will never realize what's going on and take the design and tech for granted.


View attachment 627554

 

[pt19713]

My MY starts blowing warm air within ~15s.

Have you tried hitting the front defrost twice so it's on high/red? It consumes HUGE energy! I was charging last night (6 kW), hit the defrost to clear the fog on my windows and charge time estimates went from ~4 hours climbed steadily to >>12 hours within a minute. Turing it off dropped the estimate back down.

(Aside: We don't really have cold weather in the Bay Area, CA--I think the car said it was 71deg yesterday and today is shorts and t-shirt weather so it's probably the same ).

I think what you saw were the Stator motors warming up, which is what was consuming the web energy. The heat pump itself doesn't require that much energy.

 

[Brian-MS90D]

Tesla has designed the 3 and Y motors to create a non-motive power waveform to produce heat in the stator motor

So then in effective the cabin heating system is two components of:

1. Electric heat (although via the motor instead of a toaster oven element
2. Heat pump

That's the good news I'm happy to hear. I don't care how they do it, as long as it heats up quick like the S/X does
This thread has been awesome, thanks to everyone who contributed especially pt19713.

 

[pt19713]

So then in effective the cabin heating system is two components of:

1. Electric heat (although via the motor instead of a toaster oven element
2. Heat pump

That's the good news I'm happy to hear. I don't care how they do it, as long as it heats up quick like the S/X does
This thread has been awesome, thanks to everyone who contributed especially pt19713.

No, there's no heating element, just the heat pump.

Edit: sorry, reread your statement. Yeah, #1 is coming from the motors indirectly.

 

[pkitch]

Tesla has designed the 3 and Y motors to create a non-motive power waveform to produce heat in the stator motor.
It's pretty amazing how fast the motors warm up, as shown in my previous graph.

What I didn't post (since it didn't apply to the previous questions) was the graph of the motor and battery pack temps after the preconditioning. Here's the graph showing the various points of data for a 33 minute drive.

Weather conditions were pretty bad, 26F, roads were icy with packed snow, and further into the drive it got a little better with mostly wet and slushy roads. Here are the stats from the drive:
* Front Stator motor started at 190F, finished at 77F
* Rear Stator Motor started at 162F, finished at 95F
* Battery inlet temp started at 75F, finished at 61F
* Cell Temp Mid (battery pack) started at 69F, finished at 67F
* Car set to Chill mode, low brake regen. Topography fairly flat.

The car was able to maintain the battery pack temp for about 10 minutes since the front and rear motors (blue and pink line) were above 100F during that duration. You can also see the battery inlet temp (temp of the refrigerant prior to going through the battery pack) dipping at around the 10 minute mark. This was when I turned on the heat for a little bit, so the system pulled the heat that was originally directed to the battery to go into the cabin. Visually you can see on the red line when I did this.

The car has a lot of amazing tech going on in the background. Most owners will never realize what's going on and take the design and tech for granted.


View attachment 627554

Again really great info, thanks for sharing it. I continue to be impressed with the tech (and net output)...

 

[mark95476]

Thanks for your response, as always.

I checked last night and the front-defrost (on high) definitely consumes way more power than the cabin heaters alone.

When using the cabin heaters alone (65 ambient to 70 target) the charge time roughly doubled from 2.x hours to 4.5 hours relatively quickly and then settled down to ~2.5 hours after hitting my 70deg target temp.

So (grossly),
Front-defrost > 6 kW
Cabin heaters < 6 kW

I think what you saw were the Stator motors warming up, which is what was consuming the web energy. The heat pump itself doesn't require that much energy.

 

[pt19713]

Thanks for your response, as always.

I checked last night and the front-defrost (on high) definitely consumes way more power than the cabin heaters alone.

When using the cabin heaters alone (65 ambient to 70 target) the charge time roughly doubled from 2.x hours to 4.5 hours relatively quickly and then settled down to ~2.5 hours after hitting my 70deg target temp.

So (grossly),
Front-defrost > 6 kW
Cabin heaters < 6 kW

I'll have to test this over a few days. Unfortunately I'm working from home again so my driving is limited, but I still need to drive to the grocery store on occasion.
I'll run a test to pre-condition with the front window defrost and another day I'll log the data through the in cabin heat pre-conditioning. All my pre-conditioning data is done with the normal cabin heat and not the defrost.

The weird thing is I've done drives and my log data is with the defrost only, which doesn't draw a lot of energy.

 

[pt19713]

Thanks for your response, as always.

I checked last night and the front-defrost (on high) definitely consumes way more power than the cabin heaters alone.

When using the cabin heaters alone (65 ambient to 70 target) the charge time roughly doubled from 2.x hours to 4.5 hours relatively quickly and then settled down to ~2.5 hours after hitting my 70deg target temp.

So (grossly),
Front-defrost > 6 kW
Cabin heaters < 6 kW

So I tested out the pre-conditioning with the defrost set to HI, for 10 ten minutes.

It looks like it's taking an extra 3-4 kW to pre-condition with the defrost set to HI versus setting an in-cabin temp at a normal setting.
Normally when I pre-condition, my cabin is set to 66-67F, and there's about 4-4.5 kW going to the battery. The graph shows pretty much all the energy from the Gen3 HPWC going straight to power the car, and at a few points, it was pulling a little from the battery.

 

[Big Earl]

There is a lot of confusion in this thread about how the Model Y’s heating system is designed and functions.

Here is an excellent three-part video series detailing exactly how the 12 heating modes and 3 cooling modes of the 3/Y heat pump system work.

 

[mark95476]

Thanks for running this test and pulling the data. It's always good to see numbers and graphs.

So I tested out the pre-conditioning with the defrost set to HI, for 10 ten minutes.

It looks like it's taking an extra 3-4 kW to pre-condition with the defrost set to HI versus setting an in-cabin temp at a normal setting.
Normally when I pre-condition, my cabin is set to 66-67F, and there's about 4-4.5 kW going to the battery. The graph shows pretty much all the energy from the Gen3 HPWC going straight to power the car, and at a few points, it was pulling a little from the battery.

 

[Reborn]

Point is with my older Model 3 I could jump right in, no preconditioning and be comfortable in 2-3 minutes.

i agree! The Y takes much longer than the 3 to heat up and uses much more energy as well.

 

[rrolsbe]

I don't know if this is a strategic move by Tesla or by design, possibly both and pure genius. Most likely the latter. While parked, the front motor is always warmer faster and at higher temps (up to 210F). The rear motor I've seen maxed out at 170F.

For the single motor, we'll just have to wait and see, and hope an owner with one gets the hardware with the SMT app to pull the data (or I can borrow one for 20 minutes to test, but not many Teslas in my area and I don't have the Bjorn-credibility lol).
I don't really follow the Model 3 forums and groups, so I don't know if any cold weather 2021 Model 3 SR have talked about cold weather pre-conditioning, cabin heating, etc.

Maybe the following has something to do with the rear stator max temp of 170F?

When heated above 176° Fahrenheit (80° Celsius), magnets will quickly lose their magnetic properties. The magnet will become permanently demagnetized if exposed to these temperatures for a certain length of time or heated at a significantly higher temperature (Curie temperature).Jun 10, 2014

 

[pt19713]

Maybe the following has something to do with the rear stator max temp of 170F?

When heated above 176° Fahrenheit (80° Celsius), magnets will quickly lose their magnetic properties. The magnet will become permanently demagnetized if exposed to these temperatures for a certain length of time or heated at a significantly higher temperature (Curie temperature).Jun 10, 2014

I've gotten the rear motors to 196F.