There's an AC button, why not a heater button?

There's an AC button, why not a heater button?

When the weather is mild I would prefer to just have the CC on "vent" where you get some airflow but no heat or AC - thus saving battery. You can turn the AC off with the button (though it took me a bit to figure out which was on and which was off), but if the temp outside is a bit lower than your setting it could turn the heat on. I don't want to have to dial down the temp setting all the time to make sure this doesn't happen. It would be nice to have this capability, along with a little icon at the bottom of the screen by the fan & temp to show if the heat and/or AC are active.

Bighorn | 31 oktober 2018

AC conditions the air. Doesn’t mean it’s cold.

dbwitt | 31 oktober 2018

Agree on this Effopec. I wish there was an easy way to just vent air, without having to change the temps. Also, it was at a little easier on V8 to see when the heater was being used with the orange color used in the climate controls. I don't see that on the V9 version though.

sroh | 31 oktober 2018

I've been wondering if I'm missing something on this issue as well. Especially since we know the heater has an even bigger impact on energy usage, it should be something that is easy to see and adjust.

jjgunn | 31 oktober 2018

Bighorn is always right....

Increase the temp setting & see what happens while the AC is on.

calvin940 | 31 oktober 2018

More is not always better.

Alex_SD | 31 oktober 2018

Turn the AC off and move the temperature dial to the minimum setting. There you have it: the heater is off! Now you can play with the fan speed...

vishious911 | 31 oktober 2018

I would prefer a way to adjust the AC relative to cabin temperature. Or basically give me the heater option so I can shut it down.

Because if it's 80 outside (which is what we see on the display) and say it's 72 inside (we don't see this on the display), and when I set the temperature to 76, it starts to heat up and blow hot air! WTH

hokiegir1 | 31 oktober 2018

@Alex -- The heat is not necessarily off at "Lo" (~60*F) if the interior temperature is in the mid-50's.

msm.socal | 31 oktober 2018

Bighorn +1000, why do people always thing AC means COLD? That's just not correct.

bradbomb | 31 oktober 2018

I don't think I've had a car that has had a "heater" button. Just AC as others have mentioned. However, in ICE cars, if you set temp to hot and you do not have "AC" turned on, you still get heat through the vents because the air coming in is heated by the engine and not the AC unit. In an electric car, the air is conditioned (both cool and heat) by a separate unit.

Alex_SD | 31 oktober 2018


Air conditioning (often referred to as A/C) is the process of removing heat and moisture. So, yes, A/C means cooling and never heating..

Jlomb436 | 31 oktober 2018

Also, is anything bothered by the fact that recirculation always goes off if you turn AC off? I always like to use recirculated air but if you turn the AC off while it's on and turn the AC back on, it will start using outside air. Never understood this as all 5 of my previous cars doesn't reset this option.

BostonPilot | 31 oktober 2018

Another vote here for a way to prevent the heat from coming on. It draws enough power that I want to be able to defeat it without having to change other things (like having to set the temperature to LO).

Bighorn | 31 oktober 2018

I’ll just leave this here for Alex:

Trying to educate, not debate.

jordanrichard | 31 oktober 2018

Since I have had my Model S (Mar 2014), I have never once had to "turn on the heat". The car does what it has to, to get the temperature to 70 degs.

bpaul | 31 oktober 2018

Yes! "A/C" meant "heat or cool" in my Prius, but in the Model 3 it is obvious I'm getting heat with the A/C off.

I feel like I've finally got a handle on how the environment controls work in the car, but I don't think I'll ever understand why they are that way.

Alex_SD | 31 oktober 2018


Thanks for the link! It doesn't change my statement though...
The A/C compressor could be used in combination with the hot air intake to help dehumidify the air and clear fogged up windows... So, in winter, the A/C primary function is de-humidification and not so much cooling. However, the heating source is always the same: engine heat...

Bighorn | 31 oktober 2018

So what about my statement do you disagree with? Heat is resistive though.

calvin940 | 31 oktober 2018

Not sure what the issue is here. In pretty much every car I have owned having AC (probably 10 total in my life), there were climate controls and an AC toggle button (most with a little light bulb or led) equivalent to this on screen implementation.

bradbomb | 31 oktober 2018

@Alex_SD Except for in a complete Electric car. The heating source is not the engine heat since there is no engine, just an electric motor. Tesla has a blog post from 2006 about it

Effopec | 31 oktober 2018

@jordanrichard - it's not that I want to "turn on the heat", I want to be able to turn off the heat. In ICE cars heat is free, so no reason to turn it off. In EV's heat is not free. It is often in the 50's-60's in the morning and 80's or higher in the afternoon here this time of year. For me, 50's is not low enough to need heat, I'd just rather have a little vented air. So I'd often turn the temp all the way down and AC off so the heater doesn't run. But then in the afternoon I don't want it to be in the bake in the sun in the 80's, so I need to turn the temp back up and the AC on. I would like to be able to just leave the temp setting at 72 and decide whether to allow either AC or heat to come on with separate buttons. More of an economy setting.

Alex_SD | 31 oktober 2018

@brad. Yes, absolutely. EVs are different.

@bighorn. I might be arguing a little bit more about concepts and principles here. Even de-humidification is performed through cooling. The basic principle is the same: hot air holds more moisture than cold air. So, the air is first cooled down, the moisture is recovered as water and than the air is heated up again to a more comfortable temperature by mixing it with hot air. The A/C compressor always does the same thing: cools the air down and recovers the humidity as water.

Airplanes have the same cabin design: they use A/C packs to cool down and de-humidify the cabin air and than the air is recombined with hot jet engine air to a more comfortable temperature...

Goofy Runner | 31 oktober 2018

The temperature control should be somewhat similar to a Nest Thermostat. There is a Summer, Winter and Auto mode. It would be nice to disable the heat just as we can disable the AC. Unlike a home thermostat there are sometimes which require both the AC and heat to defrost the front window. It would be nice if there was an easy way to control these (master switch) without having to overthink setting the temperature.

jefjes | 31 oktober 2018

I wouldn't mind having a heater button or maybe a button labeled vent only so outside air could be brought in without heating or cooling and no need to go into the menu to do that. Once venting is no longer desired, it could be turned back off and the HVAC system could be returned to your previous settings without menu adjustments again. One small peeve I also have is the way the defrost button works. When pressed if first comes on blue blowing cool air, press 2 blows heated air which is fine but then once the fogging has been removed, press 3 turns the defroster off but leaves the heat on even if I had previously turned it off. That requires me to turn the heat back off by holding the fan icon down or going back into the HVAC menu to do so. I want to use mainly seat heat so I usually keep the HVAC off after preheating the car on plug power but the windows still need defogging from time to time. The current set up requires four or more button presses to go from seat heat only back to seat heat only just to defog the windows.

bradbomb | 31 oktober 2018

@effopec I keep my car on Manual AC ON and the temp setting to LO. I have yet to have the heat turn on me in the morning when the car is still cool.

HighlandPony | 31 oktober 2018

What if the button label as changed to ‘Vent Only’ instead of A/C? If selected it wouldn’t heat or cool, simply provide airflow. That would provide the most useful functionality for me. If you want temperature control use auto, if not use vent only.

bradbomb | 31 oktober 2018

@HighlandPony Have you had a car before that has a vent only button? My '93 Camry, '98 Mustang, '05 Explorer, '08 Corolla, & '13 Mustang all had an A/C button that when turned off, would put the car in vent only if the fan was on

bradbomb | 31 oktober 2018

Correction, my '98 Mustang had a setting on the knob dial for "Vent".

gmr6415 | 31 oktober 2018

I don't know about other vehicles, but my 1997 Dodge Dakota runs the AC while the heat is on to help defog the windshield and dry out the air in the cabin. You can hear the compressor coming on and off the whole time the heat is on no matter how cold it gets.

All said, I would like an easier way to just get outside air moving through the cabin. A touchscreen button to turn off the heat seems like it would be the easiest way with the leas amount of steps especially as the outside temp changes through the day.

seattlemag | 31 oktober 2018

@Effopec, if by "ICE cars heat is free" you mean it's a natural by product of an inefficient combustion process that costs multiples more to operate than an EV, then yes you're right ;).

And TECHNICALLY it isn't free as it's stealing from the engine, which at startup wants all the heat it can get in cold weather. The faster it warms up, the sooner it can stop running rich air/gas mixture. So to hyper-mile your ICE you'd actually want to turn heat off until reaching operating temp... But I digress :).

All joking aside, I think you can get the result you're looking for by simply turning off A/C and manually setting temperature to low.... just like you would in your ICE car:
"So I'd often turn the temp all the way down and AC off so the heater doesn't run"

Try that out and see if you're happy with the results.

When the temp started cooling in the mornings, I spent a lot of time and effort to find that balance of the highest possible "no heat" setting and determined that LOW or simply OFF is the best when I wanted to hyper-mile. The cabin would eventually cool to a temperature where I would get too cold and needed some heat anyway, and at that point the heater would have to be turned on.

Now I don't even bother, as I've determined it's worth the increased energy use to be comfortable on my 50 mile round-trip commute. Isn't that the reason I bought a $60k car anyway? But it is a personal decision and YMMV. Happy driving!

mikehen08 | 1 november 2018

After reading this thread, I feel like I have been using my temperature controls wrong in every car I've owned. I always thought A/C was for cold air only, not hot air. I always wondered why my Silverado would automatically turn on A/C when I had heat set to max. It drove me crazy!

Even in my Tesla I kept turning A/C off when it is cold out and I need to warm up the car a bit so I can feel my hands. I set it to 72 and let it do its thing. But it was driving me crazy that my windshield wasn't defrosting properly so I will try it with A/C turned on now that I know it removes moisture.

Every day is a school day!

terminator9 | 1 november 2018

Interesting titbit of information... HVAC = heating, ventilation, and air conditioning.
If AC meant also heating, then why would it be separate. It should be called VAC. Outside of US, when central HVAC until isn't an option in the house, when AC term is used, it only means cooling. They have separate units for heating (heaters) if needed.

With that said, the "AC" button in cars have always confused me as heating (at least in ICE cars) works with our without it.