Staying comfortable in Extreme Cold

[Chopr147]

I agree as well, at this price level of automobile, we have the right to expect better performance. In my personal opinion, the Sub Zero package (that means BELOW ZERO, Tesla ) should include additional insulation in all of the doors, the fender wells, the floor, the roof and the "firewall" That extra insulation probably wouldn't add more than 100 lbs, if that. I'd happily take a couple miles of range hit in the summer for the extra comfort and added range in the winter due to the extra weight. I also feel the size of the heater should be increased in that package. I don't understand why they don't use an A/C compressor that you can run in reverse as a heat pump, MUCH more efficient then a resistive heater. I have one on the roof of my RV, so I know small packaging is possible. I realize they lose efficiency below 15 degrees or so and stop working altogether below zero, but that would be the reason for the resistive heater backup. Considering typical winter days are in the teens or higher, I feel the heap pump would be an excellent addition. I, for one, would happily pay 2-3,000 extra for a true Sub Zero Package if it included these items.

Thanks for the write-up. While I have an S and the floor heat is really very poor, the heat in the cabin is very good.
Quick question: OK so you have the heat on 75 and blower at 3. As far as energy usage does it make much difference on the blower rate? I don't think it does but not sure.

 

[Pwdr Extreme]

Are you in Range Mode? You may have a better thermal situation with full heater power, i.e. with Range Mode off. Of course you might not get very far that way, but at least you'll be warm...

Definitely not in Range Mode, anything colder than about 30 - 40 or so and range mode doesn't provide enough heat.

 

[Pwdr Extreme]

Thanks for the write-up. While I have an S and the floor heat is really very poor, the heat in the cabin is very good.
Quick question: OK so you have the heat on 75 and blower at 3. As far as energy usage does it make much difference on the blower rate? I don't think it does but not sure.

Blower speed definitely impacts it some for sure, but it's most likely running the heater on full that is the biggest power draw. I have the blower set much higher than 3 in order to get enough heat.

 

[aesculus]

I have added a small cardboard deflector (only about 1/2 inch deep) for the driver foot heat to direct some hot air more to the inside foot.

Can you share a picture of your deflector with us?

 

[Chopr147]

I have the blower set much higher than 3 in order to get enough heat.

Well, I guess I can see that when the temp. is -24!!!!!
Difference with this car is planning. Something I did not have to concern myself with when I could fill up on every corner

 

[AudubonB]

Congrats to PowderX for hitting -31ºF - I've not done that in the Tesla. But I do have real extreme driving experience - into the minus 50s - and perhaps some might benefit from one or more of the following observations.

1. The cavernous interior of all my Crew Cabs - four over the past two dozen years - mean that even the monstrous BTU output of their diesel engines is not sufficient to keep up with the heat loss of all that glass and thinly insulated metal skin. It is not possible to keep both windshield AND driver's side window defrosted simultaneously. That being the case in such an ICE, it is a fool's errand to expect an EV to perform satisfactorily.

2. Cold weather driving prep in Alaska means that for the bottom half of each year, you always carry survival gear: you expect to go "camping" at -20, -30 -40 or worse. That is, you anticipate a breakdown with assistance many hours away. With such gear, then, you have the means to stay warm whilst driving. Me - I unabashedly place an appropriate coat over thighs, knees and upper calfs - enough not to encumber lower leg braking and accelerating action. Obviously, the colder it is, the heavier the coat - I've resorted to my expedition sleeping bag at times.

3. Our Alaskan-manufactured pickup camper is equipped with a so-called "Arctic Grade Insulation Package". I assisted the manufacturer with the insulation - I know how very good the material is. And it's inadequate. That is, absent a real heat source (in our case, a 22,000 BTU propane heater), the insulation maintains heat only slightly better than your average kitchen colander. With that experiential base, I would counsel no one to waste the abovementioned $2-3,000 on a "proper" insulation package of an EV's door and other body panels. That's money up in smoke. So to speak.

4. I can envision a highly efficient catalytic propane heater eventually being offered in otherwise hydrocarbon-free EVs for severe weather conditions. Consumption rates of 800kWh/mi and more otherwise will necessitate a SpC density coverage throughout the North Country that would exceed what SoCal now enjoys. That'd be something: 3,000 SpCs in Alaska; 2,000 in Yukon; 2,000 in Northwest Territory....I don't think so!

5. In the meantime, hearken well to what Early Icicles like Pwdr Extreme write, and plan your travels accordingly.

 

[Garlan Garner]

It was a little colder today, but it was bright and sunny. Left my garage in Belgrade which was 40 degrees inside headed to Livingston 37 miles and one mountain pass away. 237 rated miles at 80% charge. 19 miles later I had used up 16% of my battery, or about 60 rated miles. This is how long it took the car to heat the battery pack to the point the dashes were gone limiting the regen. I was using about 790 wh/mi and hadn't even began the climb yet. Heating the battery requires a tremendous amount of power it seems. On the bright side, due to the sun shining in the windows allowing for some passive heating, I was able to lower the cabin temp down to 76 and set the fan to auto which selected a speed of 7. I tried full auto HVAC and of course it turned on recirculation and instantly fogged the windows. On the way home after the car had sat outside for several hours in -5 weather, it took 30 miles before the battery was fully warmed up. Outside temps finally had moved to the positive side, it was now 1 degree. I stopped at the Bozeman supercharger with a total drive of 68 miles, yet I chewed through 150 rated miles of power. Moral of the story, when you add in a cold battery to the mix, range REALLY suffers. (My previous tests were all right after leaving a charger so the battery was warm)

I think that's about all the testing I'm going to do, unless somebody has any specific questions, tomorrow is supposed to finally start warming up around here.

Hope this info has helped!

More importantly....why are you listening to that song?

 

[crash1977mtl]

The rear heater is a joke, we turned it up 80 degrees and turned the fan speed down to 3 so it wasn't blowing too hard, the air coming from the vents was Luke warm at best, I'd estimate 70 degrees or so. Any higher fan speeds and the volume of air actually made it colder. Fortunately in the middle row I was very comfortable just from the front heater. Not sure what the 3rd row would be like.

So there you have it, cheers! =)

I just had delivered a MX 90D in Montreal. Today it was ~ -20C (-2.2F) north of Montreal. The rear heaters do not work - period. My kids where complaining about the lack of heat.. like you said, if you turn down the fan to 2 you can feel basically room temperature air...anything higher and it creates a cold draft.

I can also confirm the thermostat reading in the car to be totally off... I had to put my temp to 25C (77F) for it to be equivalent to say 70F in a ICE car and maintain comfort.

 

[Pwdr Extreme]

Congrats to PowderX for hitting -31ºF - I've not done that in the Tesla. But I do have real extreme driving experience - into the minus 50s - and perhaps some might benefit from one or more of the following observations.

1. The cavernous interior of all my Crew Cabs - four over the past two dozen years - mean that even the monstrous BTU output of their diesel engines is not sufficient to keep up with the heat loss of all that glass and thinly insulated metal skin. It is not possible to keep both windshield AND driver's side window defrosted simultaneously. That being the case in such an ICE, it is a fool's errand to expect an EV to perform satisfactorily.

3. Our Alaskan-manufactured pickup camper is equipped with a so-called "Arctic Grade Insulation Package". I assisted the manufacturer with the insulation - I know how very good the material is. And it's inadequate. That is, absent a real heat source (in our case, a 22,000 BTU propane heater), the insulation maintains heat only slightly better than your average kitchen colander. With that experiential base, I would counsel no one to waste the abovementioned $2-3,000 on a "proper" insulation package of an EV's door and other body panels. That's money up in smoke. So to speak.

4. I can envision a highly efficient catalytic propane heater eventually being offered in otherwise hydrocarbon-free EVs for severe weather conditions. Consumption rates of 800kWh/mi and more otherwise will necessitate a SpC density coverage throughout the North Country that would exceed what SoCal now enjoys. That'd be something: 3,000 SpCs in Alaska; 2,000 in Yukon; 2,000 in Northwest Territory....I don't think so!

5. In the meantime, hearken well to what Early Icicles like Pwdr Extreme write, and plan your travels accordingly.

-50 has me beat, I think the coldest I've seen was mid -40's, -90 with windchill, now that is miserable! What kind of truck do you have? My Megacab Ram has no trouble keeping the interior warm, of course I use a winter front when it drops into -10 range and colder, I'm sure you do the same.

Good friends of mine were the owners of Bigfoot Camper, their truck camper was designed to stay comfortable down to -40, I personally never used it that cold, but I did use it in below zero temps and it was always comfortable.

I do disagree with you on the insulation, certainly you aren't going to get an R factor more than about 6-8 but seeing how big of a difference just the insulation shield made on the upper window, I do think it would make a noticeable difference. I intend on installing some sound deadening / insulation on my car once I actually get it. Figure I can make it quieter while helping winter performance both.

 

[TLej]

Without deflecting the hot foot air most ends up on the outside foot.
View attachment 209310

Interesting comment; this evening I noticed a similar effect. When driving with cruise on, my tendency is to pull my left foot back towards the seat instead of leaving it stretched out. Today on the drive home from work, my right foot was a little chilly and as soon as I moved my left foot forward to the dead pedal, I noticed immediately my right foot got warmer. Maybe the design anticipates "bouncing" air off the left leg in order to keep the foot area warm? Dunno.

No doubt the car is somewhat limited in its heating abilities, but honestly other than one trip I did with Range Mode on (never again!) I've never been uncomfortably cold and have never taken extra measures to stay warm. I should mention I almost always drive in dress shoes or running shoes; if I had my light winter boots on, my feet would never be cold.

It certainly is hard on the range though; I left the house this morning at 90%, drove 83 kilometres over two trips (41 km to work, cold-soaked for 9 hours, 42 km home), and arrived back home at 58%. I miss my 150 Wh/km!

 

[MorrisonHiker]

I should mention I almost always drive in dress shoes or running shoes; if I had my light winter boots on, my feet would never be cold.

Some people might have other problems when driving with winter boots: David Noland suggests Model S pedal placement is a safety hazard

 

[TLej]

Some people might have other problems when driving with winter boots: David Noland suggests Model S pedal placement is a safety hazard

The main reason I rarely wear mine when driving any vehicle. Not specific to the Model S, in fact a bigger issue with my manual Outback.

 

[AudubonB]

What kind of truck do you have? My Megacab Ram has no trouble keeping the interior warm, of course I use a winter front when it drops into -10 range and colder, I'm sure you do the same...Good friends of mine were the owners of Bigfoot Camper, their truck camper was designed to stay comfortable down to -40, I personally never used it that cold, but I did use it in below zero temps and it was always comfortable.

I do disagree with you on the insulation, certainly you aren't going to get an R factor more than about 6-8 but seeing how big of a difference just the insulation shield made on the upper window, I do think it would make a noticeable difference. I intend on installing some sound deadening / insulation on my car once I actually get it. Figure I can make it quieter while helping winter performance both.

1. Fords, always. And always diesels - which, as a virtue of their greater efficiency, do NOT generate as much heat as gassers, thus have less to throw into passenger cabs. Do you drive diesel or gas?

2. Bigfoots have good reputation. Ours is a Cache Camper and, as I wrote, are designed and built in Alaska. They also are good in as cold a temperature as we get to...my point is that it, a Bigfoot, and any vehicle's interior ALL need an ancillary heat source; to reiterate forcefully: EV drivers should not expect their vehicles' battery packs to act as an adequate heat provider in cold conditions.

3. Insulation - I have to agree, not disagree, with you....sortakinda:

• The presence of insulation is better than its absence, but the company must be careful about performing its cost-benefit due diligence.
• Wind-leak gaskets & seals are an area to be perfected. Any leakage is instantly noticeable and detrimental when ambient is, say, -20ºF. Here is where Tesla Motors has SpaceX to use to its advantage - surely there should be some crossover technology?

 

[Lon12]

Can you share a picture of your deflector with us?

Well I made it out of easy prototyping material (toilet paper cardboard roll, approx. 2.75"x1.5") . That way I can cut it down easily as I trial and error the best size. The slight curve of the roll also helps deflect the hot air. I used some double sided clear scrapbooking tape to place it.
Here are the before and after FLIR shots. You can just make out the deflector between both pedals near the top of the picture. I think it is deflecting too much air now. The dead pedal area is now a lot cooler. But my thinking is that you can move your left foot anywhere you like but your driving foot needs to stay close to the brake and accelerator.
We are forecast to get down below -30C this week so I might be able to get some more testing in.

 

[David29]

One small point. In the Model S, the temperature sensor is located in the center console, beneath the armrest. There is a small circle of holes in the upholstery that apparently admit the air to be sensed. So that is pretty remote from the cold surfaces of the door and footwell. Because the Model X and S are similar in other ways, I suspect the one for Model X is similarly located.

Today when I was driving around in some moderately chilly air (temps in low 20Fs), the cabin temperature started to get uncomfortably hot. I had the heat set for 68 or 69, in Auto. What I pretty quickly discovered was that something was blocking those air holes. I had a thin plastic bag on top of the lower console, and it had slid back so that part of the bag was blocking the holes. As soon as I moved the plastic bag, the fan speed and temperature both dropped, and quickly. (I had left the bag there to help protect the console from the damp hat and gloves I took off after clearing the car of snow and getting in to drive.)

So the sensor needs unimpeded air flow to sense the temperature correctly.

 

[Pwdr Extreme]

1. Fords, always. And always diesels - which, as a virtue of their greater efficiency, do NOT generate as much heat as gassers, thus have less to throw into passenger cabs. Do you drive diesel or gas?

2. Bigfoots have good reputation. Ours is a Cache Camper and, as I wrote, are designed and built in Alaska. They also are good in as cold a temperature as we get to...my point is that it, a Bigfoot, and any vehicle's interior ALL need an ancillary heat source; to reiterate forcefully: EV drivers should not expect their vehicles' battery packs to act as an adequate heat provider in cold conditions.

3. Insulation - I have to agree, not disagree, with you....sortakinda:

• The presence of insulation is better than its absence, but the company must be careful about performing its cost-benefit due diligence.
• Wind-leak gaskets & seals are an area to be perfected. Any leakage is instantly noticeable and detrimental when ambient is, say, -20ºF. Here is where Tesla Motors has SpaceX to use to its advantage - surely there should be some crossover technology?

Ah, a Ford man, that explains everything! LOL. J/K Yes, I always drive diesels, (Duramax & Cummins, Cummins, Detroit and Cat in the big rigs) which are hard to keep warm unless you are really working them, hence the reason for the winter fronts.

I have to agree with you, there certainly seems to be some air leaking in somewhere, It's quite surprising just how quickly the cabin temp will drop as soon as I get on the highway after driving around town. It's almost like as you go down the on ramp, you'd better raise the temp a few degrees and the blower speed a few notches. I wouldn't think the "windchill factor" could make that big of a difference that quickly.

Yes, Model X seems to have the sensor in the same location as the Model S, I wondered what that vent was.

Bioweapon mode does NOT fog the windows, in fact I put it into full auto mode and let the windows fog a bit, then switched to Bio mode, after a few miles the windows cleared.

Edit: You bring up an interesting idea with a catalytic heater, when the VW bug first came out, that was what it used for heat. I know having to carry the little lantern sized propane bottles defeats the purpose of an all electric vehicle, but it sure would be nice to have warmth, and range both.

 

[MDMGSO47]

I understand that Florida, So Cal and Arizona are very nice this time of year

 

[xWing88]

I'm starting a new thread since this is really about driving in pretty extreme conditions

Car is a new Model X P100DL with 22" wheels.

Lastnight a friend and I went on a 300 mile road trip at -20 degrees Fahrenheit to deliberately see two things:

1. Is it possible to stay comfortable without "wrapping up in a blanket"?
2. Just how much battery power will we use?

The trip was Bozeman, MT supercharger to Billings, MT supercharger. On the way down temps ranged from -9 to a low of -23, the average was about -14 overall. We left Bozeman at 96% charge with a rated range of 270 miles. 140 actual miles to the Billings supercharger, thus leaving me 130 rated miles of margin. For reference Bozeman is 4800' elevation and Billings is 3100' with 2 substantial mountain passes in between.

The entire trip we both used our seat heaters set on 1, I turned the steering wheel heat off and on throughout to maintain comfort. (REALLY wish the wheel had a high and low and there was a much easier way to turn it off and on, having to go thru a couple pages on the touch screen is just plain silly)

Driving speed was 75mph with some areas slowing to 60-65 due to road conditions. Very little wind. On the way down I had cabin heat set to 78, outside air and fan speed set to 9. (Any higher fan speed forces recirculation and instantly fogs the windows). My buddy and I were both wearing jackets, but otherwise not dressed for winter, so to speak. We were both mostly comfortable, but our legs were on the cold side, my left leg especially cold along the driver's door, to the point I was uncomfortable. So my initial thoughts were if I had brought a blanket to lay across my legs, I would have been completely comfortable, my buddy agreed. Conclusion, having to use a blanket in a $120,000+ car shouldn't be necessary, but given the fact that 20 below is pretty extreme conditions, it's certainly not the end of the world and acceptable. I have driven in even colder conditions in numerous ICE vehicles and not even needed my jacket for reference. So the conclusion is the heater is barely adequate at best, but at least it's "doable" to drive in the cold.

When I arrived I had 21 rated miles left, so I used 249 rated miles to drive 140 actual miles, average was 584 wh/mi. You'd better have PLENTY of excess range stored up before setting out in these conditions.

Now the return trip...

Charged to 95%, 267 rated miles range.

Temps were more consistently in the -20 range, with a low of -27. I'd say the average was pretty much -20. Heater set to the same level. We were both uncomfortable, our legs were cold, so that little bit of difference was definitely the breaking point and had surpassed the limits of the heater. Well at least now I know. Then I got the idea to install the sun shade on the upper half of the windshield. What a difference!!!! It hangs down maybe an inch or so from the glass creating just enough air space for an insulating pocket. Holding our hands a few inches below the glass before we could definitely feel very cold air dropping from the glass and landing right on our legs. After the sun shade we couldn't feel the cold air. 20 miles later our legs were warm and we were both completely comfortable. Great! However, about 40 miles in to the trip I started getting the slow down messages, decided there is no way to make Bozeman unless we either drastically slow down, or lower the temp back to the uncomfortable range. Stopped at the Big Timber supercharger 60 miles from Bozeman instead. Drove only 80 miles, used 165 rated miles. 698 wh/hr. Climbing definitely was hurting us. Arrived back home safe and sound in Belgrade with an average usage for the trip at 630 wh/hr.

So overall what I learned is the sun shield makes a HUGE difference (I have the evanex insulation panel I'm going to install between the window and sunshield and try again tonight) and you'd better have at least twice your actual distance in rated range available to make it. My car is a 90D with 20" wheels once I receive it, so my actual driving distance is probably pretty close to the P100D with 22's, if not slightly better.

Again, the point of this wasn't to see "how far we could go if we have to" it was to see how the car would work in very cold conditions without making any sacrifices to comfort or speed. Obviously I know if I had slowed down, wrapped up in blanket and put on gloves and a hat I could have driven substantially further, but I didn't buy a $120,000 car to not be completely comfortable driving it the way I want. =)

Oh, I want to add for the last 10 miles of the trip I jumped in the middle row of this 7 seater. Very comfortable temperature wise, but the right side of my face so close to the window would have probably started to get uncomfortable after several more miles. The 6 seater, which is what I ordered seems to have the outer seats set closer to the middle, I didn't remember my shoulders actually being against the door when I set in the back of the showroom 6 seater, I hope this is the case.
The rear heater is a joke, we turned it up 80 degrees and turned the fan speed down to 3 so it wasn't blowing too hard, the air coming from the vents was Luke warm at best, I'd estimate 70 degrees or so. Any higher fan speeds and the volume of air actually made it colder. Fortunately in the middle row I was very comfortable just from the front heater. Not sure what the 3rd row would be like.

So there you have it, cheers! =)

We had the same problem and actually took it into the Fremont SC. The problem is the worst in the 3rd row. We were on our way back from Tahoe to the Bay Area. We have 2 kids in the last row, and 2 kids in the middle row. The kids in the back were complaining of the cold. We blasted the rear heater and it actually made it worse. The only thing we could do to keep it warm was blast the front heater (and hold it travels to the back) and have the kids wear their snow jackets. The service center said it's by design, because the battery get the priority when it comes to heating and cold weather. They also recommended running the fan at a lower speed.

 

[Pwdr Extreme]

Another update to this thread regarding performance after the recent January 12th software update:

Yesterday I drove the loaner MX P100DL I did all of this testing in back to the service center to finally pick up my MX, YAY! Anyway, I performed a software update the night before. Headed down thru Yellowstone Park temps were averaging around -15 with -27 being the lowest, much the same conditions as my previous tests, it was also dark outside, so no passive heating from the sun. I had the HVAC system set to full auto mode at 72 degrees which worked well in the 30 degree weather 3 days prior (and the last time I drove it). After driving about 50 miles it finally dawned on me I was completely comfortable and the window wasn't fogging up. Not to mention my girlfriend (who is eternally freezing) wasn't even complaining. I verified all of the settings, A/C off, all other settings in auto mode. Drove in the sub zero weather about 150 miles like this, completely comfortable! (All of my winter driving has been with Range Mode off)

So it certainly seems as if Tesla recalibrated the HVAC operation in the recent upgrade. KUDOS! I wonder if they read this forum?

Unfortunately, however, once the weather warmed up to the teens, the HVAC again reverted to recirculation mode and fogged the windows. Had to manually set it to outside air as before. So they made a HUGE improvement, but still need to raise the temperature threshold before allowing recirculation mode.

In my car on the way home I had very much the same experience. Fogging windows in the teens and great performance that night with temps in the negative teens. Cabin set to 70 (girlfriend was in another vehicle) and completely comfortable.

I love the fact that Tesla is constantly making improvements! Our cars may not be perfect, but show me another manufacturer who is constantly making improvements to vehicles their customers already own.

 

[aesculus]

So it certainly seems as if Tesla recalibrated the HVAC operation in the recent upgrade. KUDOS! I wonder if they read this forum?

Cool (I mean hot).

Congrats on getting your car.