How does the temperature control work?

[Dazureus]

This might seem like odd question, but I can't find any literature to answer it. The climate control in the Model X (and S) is pretty much automatic unless you manually set the blower controls. When it's in automatic mode, does anyone know if the compressor and heater are constantly active to condition the air? For example, if the outside air is 72 F and the interior temp is set to 72 F, does the car circulate exterior air without conditioning or is the air always heated or cooled? Is the only way to vent ambient air to manually turn off A/C. turn on exterior ventilation, and manually turn set the fans to a desired speed?

 

[aesculus]

I don't have an answer for you unfortunately. With the changes to V8 this seems to have changed too. There is a lot of discussion (complaints?) on this very topic as what used to be a guaranteed re-circulation now seems to be an outside air exchange.

You can search through all of the V8 threads looking for this topic or hopefully those who have done some good experimentation will consolidate their findings here.

 

[qadaemon]

I too wish this was documented. I assume it tries to be smart about energy, but it's not perfect. If I have it set to 70 and it's 69 out, the heater obviously turns on (still new enough I can smell it). I'd like to be able to just tell it not to try heating or ac and I'll deal with my comfort from fan speed and vent direction. I'm not sure that's completely possible with this interface.

 

[EV-lutioin]

Yes, I have been wondering about this too. Is the climate system power indicator always blue... or does it turn red if the heat is on. It would be a helpful indicator if it would switch from blue to red so you could see at a glance is the car was cooling or heating and make the necessary adjustment before you get blasted with warm/cold air.

 

[Tanquen]

Yes, it'd be nice if it showed whether it was Heating or Cooling and even the inside and outside temperature. I can tell the heater is on from the smell, unfortunately.

 

[travwill]

You'll smell the heater as mentioned if set a few degrees above outside temperature and internal temp is cooler than setting also. As for being efficient, I just do it myself usually on days were its cool outside but say your cabin is warmed up from the Sun some. Just go into the controls and 1) turn A/C OFF, 2) choose outside air (nice and cool), and 3) choose a fan speed and that will disable auto fan speed - then that is obviously one of the steering wheel controls you can still modify easily, etc.

Those days will be short lived here as soon its max heat heat heat... I really wish we had the ability in the app still, for like third year now, to control all the subzero options remotely. Peeves me that you have to get into the car and THEN turn on defrosters, wiper defrosters, heated steering wheel and seats, etc. Defeats that purpose really...

 

[jdw]

You can set the temperature to LO and turn the AC off and you will just get fresh air or recirculated air depending upon that setting.

 

[psgabin]

You'll smell the heater as mentioned if set a few degrees above outside temperature and internal temp is cooler than setting also. As for being efficient, I just do it myself usually on days were its cool outside but say your cabin is warmed up from the Sun some. Just go into the controls and 1) turn A/C OFF, 2) choose outside air (nice and cool), and 3) choose a fan speed and that will disable auto fan speed - then that is obviously one of the steering wheel controls you can still modify easily, etc.

Those days will be short lived here as soon its max heat heat heat... I really wish we had the ability in the app still, for like third year now, to control all the subzero options remotely. Peeves me that you have to get into the car and THEN turn on defrosters, wiper defrosters, heated steering wheel and seats, etc. Defeats that purpose really...

AGREED

 

[Solarman004]

Just go into the controls and 1) turn A/C OFF, 2) choose outside air (nice and cool), and 3) choose a fan speed and that will disable auto fan speed - then that is obviously one of the steering wheel controls you can still modify easily, etc.

Don't forget to also also turn off rear climate control if you have rear passengers, or you will still be using A/C energy. If you have selected outside air and A/C off for the front, the rear area will get ventilation air from the center (console) register, but the door pillar registers will provide no airflow.

 

[Tanquen]

You'll smell the heater as mentioned if set a few degrees above outside temperature and internal temp is cooler than setting also...

Sorry, what now? I've used lot of car heaters and I've known their on from heat not the smell. So its cold outside and inside the car, OK sounds normal. You set the temperature above that, ok but why is it ok for it to smell and how would you user the heater differently? Are you saying it's just cold enough for the heating element to be on but the fan is on low so it's getting too hot and smells a little like burning electronics.

 

[Saghost]

Sorry, what now? I've used lot of car heaters and I've known their on from heat not the smell. So its cold outside and inside the car, OK sounds normal. You set the temperature above that, ok but why is it ok for it to smell and how would you user the heater differently? Are you saying it's just cold enough for the heating element to be on but the fan is on low so it's getting too hot and smells a little like burning electronics.

Tesla uses a high voltage PTC heater to heat the cabin air directly, and the elements appear to get hot enough to 'burn dust' so you get a little of that electric heater smell.

That's the only thing I've actually smelled in my X, thanks to the premium package air filters.

 

[FarmerDave]

Tesla uses a high voltage PTC heater to heat the cabin air directly, and the elements appear to get hot enough to 'burn dust' so you get a little of that electric heater smell.

That's the only thing I've actually smelled in my X, thanks to the premium package air filters.

What is a PTC heater? It was my understanding that the Model X uses a heat pump (AC in reverse).

 

[Saghost]

What is a PTC heater? It was my understanding that the Model X uses a heat pump (AC in reverse).

PTC stands for Positive Temperature Coefficient - meaning that they chose a resistance material which has more resistance the hotter it gets, unlike most materials - an important factor for preventing thermal runaway in electric resistance heaters.

To the best of my knowledge, no Tesla to date has a heat pump.

There is a fancy system that salvages motor/inverter waste heat to heat the battery pack in cold weather, but the schematics I've seen show just the resistance heater for the cabin. Here's the PTC heater out of a flooded model S:

https://teslamotorsclub.com/tmc/posts/1348867/

 

[beachmiles]

Yet another thread detailing the need for a better HVAC interface and user controls.
Seems to be a very common request for all Tesla models for many years now.
Seems like a complete no brainier to me. Save power, save your battery, save constantly fiddling with the AC controls.
Don't want heater on damn it!

 

[jimbo69ny]

Yet another thread detailing the need for a better HVAC interface and user controls.
Seems to be a very common request for all Tesla models for many years now.
Seems like a complete no brainier to me. Save power, save your battery, save constantly fiddling with the AC controls.
Don't want heater on damn it!

You revived a thread from 2016......

 

[beachmiles]

You revived a thread from 2016......

We still are missing some important manual HVAC controls, namely a way to disable the cabin heater. Trying to build a case that more HVAC user controls has been desired for some time now.

 

[jimbo69ny]

For at least 4 years I'd guess....

 

[bay74]

Wonder whether we'll get a "Heater OFF" button in v11. Hope so, stupid auto setting tries to heat on coolish mornings despite that being totally unnecessary.

 

[beachmiles]

For at least 4 years I'd guess....

More like 12 years since people started asking for it in 2008 with the roadster.

 

[pereiks]

Lower your expectations folks I tried fighting with HVAC inconsistent and illogical behavior in my Tesla but recently gave up and and I'm sooo happy now.

/s