turn off heater?

[AdamMacDon]

You're probably right. I only did a little testing, but I never noticed a dramatic difference between defrost with AC vs. without.

AC is 100% critical if you want to defog windows effectively and quickly. I live in a rainforest and it rains nearly 200 days of the year. I had two cars where the AC went and immediately window fog on a rainy day made the cars nearly unusable. If you live in an area where rain is a more rare occurrence and humidity is low, you can probably get away without AC, but I assure you that where I live you wouldn't last even a few minutes without it on the average day. The good news is that running the Tesla's AC compressor is very low energy draw, especially next to the 6kW PTC heater!

 

[RTPEV]

You're probably right. I only did a little testing, but I never noticed a dramatic difference between defrost with AC vs. without.

On many cars, simply engaging the front-defrost automatically engages the AC, so it would not be surprising you couldn't see a difference (unless your car is one of those that do actually let you turn off the compressor when the front-defrost is on).

 

[solarev]

Referencing OP, I have the same problem but opposite temperature. On the east cost, it is coooold. The car warms nicely to my set temperature, e.g. 68 degrees. While driving though, if it dares reaches an internal temperature of 69 degrees, the cold air turns on! While my feet were initially toasty, all of a sudden I'm feeling cold air until it drops below 68 again and ping pongs back and forth. I agree with many of the earlier posters, that a heat only or cool only button or quick menu option should be available. How unfortunate that these basic functions that we've become used to in traditional ICE cars were not considered. As much as I love the drive, I feel Tesla software functionality is still catching up with what basic functions we had become used to until now. But still, can't wait to drive it again tomorrow!

 

[derotam]

The car warms nicely to my set temperature, e.g. 68 degrees. While driving though, if it dares reaches an internal temperature of 69 degrees, the cold air turns on!

Just for technical clarity, it isn't necessarily that the "cold air turns on" as much as the heat is turning off. Ambient temperature air blowing across your body will feel colder to you, think windchill. There is also an issue with the temperature of the air coming out of the different zones(feet, body, rear seat) after the cabin reaches the set point. The rear and foot zones tend to stay warm(even hot), while the body vent will only be blowing ambient.

 

[AdamMacDon]

Just for technical clarity, it isn't necessarily that the "cold air turns on" as much as the heat is turning off. Ambient temperature air blowing across your body will feel colder to you, think windchill. There is also an issue with the temperature of the air coming out of the different zones(feet, body, rear seat) after the cabin reaches the set point. The rear and foot zones tend to stay warm(even hot), while the body vent will only be blowing ambient.

Yeah the different zone temperature problem is really annoying. My hands will be freezing in the winter but my feet are soaked in sweat. This might be more of an HVAC design issue, but I hope one day it can be addressed with a software update.

 

[solarev]

Just for technical clarity, it isn't necessarily that the "cold air turns on" as much as the heat is turning off. Ambient temperature air blowing across your body will feel colder to you, think windchill. There is also an issue with the temperature of the air coming out of the different zones(feet, body, rear seat) after the cabin reaches the set point. The rear and foot zones tend to stay warm(even hot), while the body vent will only be blowing ambient.

Yeah the different zone temperature problem is really annoying. My hands will be freezing in the winter but my feet are soaked in sweat. This might be more of an HVAC design issue, but I hope one day it can be addressed with a software update.

The only reason I disagree with you is that I've looked at my app when the cold air comes on. On the app we can see if it is hot air or cold air entering the cabin, based on our temperature setting. When it's cold outside, and you are warming the car, the arrows in the climate part of the app will be red indicating heat. On the contrary, when the air is being cooled, the arrows are blue. It is too bad that we cannot see the temperature of the air, whether warm or cool, while driving, but only on the app. But while driving, I did check what was happening. If I set the temperature to 68 degrees and the cabin was initially colder, the hot air (red arrows) would show. While driving, I check the app when I started feeling colder air coming in at my feet. The app showed the interior temperature at 69 degrees, and so the car was now trying to cool it back down to 68 degrees. The arrows were blue, indicating AC or cool air coming in. Instead of leaving the car as is and letting it cool passively, it was actively cooling the car. This is what is annoying.

If there was a heat or cool button, I assume this active switching back and forth would not happen. How hard can this be to program from the standpoint of all of the intelligent programmers at Tesla? I am a little disappointed.

 

[AdamMacDon]

The only reason I disagree with you is that I've looked at my app when the cold air comes on. On the app we can see if it is hot air or cold air entering the cabin, based on our temperature setting. When it's cold outside, and you are warming the car, the arrows in the climate part of the app will be red indicating heat. On the contrary, when the air is being cooled, the arrows are blue. It is too bad that we cannot see the temperature of the air, whether warm or cool, while driving, but only on the app. But while driving, I did check what was happening. If I set the temperature to 68 degrees and the cabin was initially colder, the hot air (red arrows) would show. While driving, I check the app when I started feeling colder air coming in at my feet. The app showed the interior temperature at 69 degrees, and so the car was now trying to cool it back down to 68 degrees. The arrows were blue, indicating AC or cool air coming in. Instead of leaving the car as is and letting it cool passively, it was actively cooling the car. This is what is annoying.

If there was a heat or cool button, I assume this active switching back and forth would not happen. How hard can this be to program from the standpoint of all of the intelligent programmers at Tesla? I am a little disappointed.

Yeah it seems easy enough to fix. Honestly the HVAC system is probably one of the biggest let downs on my SR+, maybe because the motor part of the car is so dang energy efficient, but I did some testing and even in the mild climate part of Canada I live in, running the climate control at only 20 degrees sucks almost 40% of my total energy usage for short drives. Part of it is the laws of physics, but I think some design changes like blowing hot and cold air could help address it. Or a heater off option, so I can skip using the heater without my windows fogging up!

 

[derotam]

The only reason I disagree with you is that I've looked at my app when the cold air comes on. On the app we can see if it is hot air or cold air entering the cabin, based on our temperature setting. When it's cold outside, and you are warming the car, the arrows in the climate part of the app will be red indicating heat. On the contrary, when the air is being cooled, the arrows are blue. It is too bad that we cannot see the temperature of the air, whether warm or cool, while driving, but only on the app. But while driving, I did check what was happening. If I set the temperature to 68 degrees and the cabin was initially colder, the hot air (red arrows) would show. While driving, I check the app when I started feeling colder air coming in at my feet. The app showed the interior temperature at 69 degrees, and so the car was now trying to cool it back down to 68 degrees. The arrows were blue, indicating AC or cool air coming in. Instead of leaving the car as is and letting it cool passively, it was actively cooling the car. This is what is annoying.

If there was a heat or cool button, I assume this active switching back and forth would not happen. How hard can this be to program from the standpoint of all of the intelligent programmers at Tesla? I am a little disappointed.

The colored arrows in the app are misleading at the transition temperatures. I have both seen red arrows when it isn't actually heating, and blue arrows when it wasn't actually cooling, as confirmed by the CANBus messages. I have not seen the grey arrows be wrong however. If your set point is within +/- 1 degree of ambient, the color indication in the app isn't always correct.

 

[PianoAl]

I took my neighbor's cat for a ride, and this is what happened:

 

[acarney]

Well I came here to post the same question... I guess basically there is no way to just run the fan? I often can stay warm enough on mild winter days (think 40 to 45F out) with just the heated seat... but I'll fog up the windows. I was hoping I could just run the ran on 1 to circulate the cabin with fresh air either all the time or periodically....

 

[derotam]

Well I came here to post the same question... I guess basically there is no way to just run the fan? I often can stay warm enough on mild winter days (think 40 to 45F out) with just the heated seat... but I'll fog up the windows. I was hoping I could just run the ran on 1 to circulate the cabin with fresh air either all the time or periodically....

Sure, turn off the AC and set the temp to LO. That will be no heat and no AV, then you just decide whether you want to recirc the cabin or run fresh air.

 

[beachmiles]

Sure, turn off the AC and set the temp to LO. That will be no heat and no AV, then you just decide whether you want to recirc the cabin or run fresh air.

This workaround works. The main problem being the multiple touchscreen presses required every day if if you drive from a cooler climate to a warmer climate and vice versa when you eventually want the AC on/off. My commute in LA starts by the beach at 60F, an hour later travelling inland it's 90F outside.

The fix is 2 temp setpoints, 1 low and 1 high. Anything below the low setpoint and the the heater comes on. Anything above the high setpoint and the AC comes on. Anything between these 2 setpoints is "vent mode" if you have the fan on.

In my case my low would be 60F and high 74F. So there would be 12 degrees where no AC or heater would be used, only the fan of you have it on.

 

[derotam]

This workaround works. The main problem being the multiple touchscreen presses required every day if if you drive from a cooler climate to a warmer climate and vice versa when you eventually want the AC on/off. My commute in LA starts by the beach at 60F, an hour later travelling inland it's 90F outside.

The fix is 2 temp setpoints, 1 low and 1 high. Anything below the low setpoint and the the heater comes on. Anything above the high setpoint and the AC comes on. Anything between these 2 setpoints is "vent mode" if you have the fan on.

In my case my low would be 60F and high 74F. So there would be 12 degrees where no AC or heater would be used, only the fan of you have it on.

The fix would be a heater on/off button like every other vehicle. The icing on the cake would be dual set-points which doesn't exist in vehicles. Just go wire up a house thermostat to the car! haha

 

[beachmiles]

The fix would be a heater on/off button like every other vehicle. The icing on the cake would be dual set-points which doesn't exist in vehicles. Just go wire up a house thermostat to the car! haha

I agree, since most vehicles don't have an electric heater onboard and Tesla is the king of vehicle tech I think adding a digital thermostat function would be a fairly simple thing that would kick ass as well as save energy.

 

[DaveRZ]

"Fan only" Mode! "Fan only" Mode! "Fan only" Mode!

To be honest, I've never really liked automatic HVAC all that much, in any car. Mainly because it never knows how I feel. Its great on long trips to easily keep the car at a set temp, but since it has no idea that I just came back from a hike and need FULL A/C blasting my face, or that I just sat in a cold movie theater for 3 hours and would prefer to "soak" in the warmth of the car for the first 5 minutes, it's frequently working against what I want. There's no way to fix that, you just need simple manual controls available.

One thing that they could look into would be the ability to add 3-4 HVAC user presets that you could save and name what you want. E.g., I would create a "Fan only" profile, a "Max cool" which turns on full fan and AC and blasts out of the dash vents directly forward, a "Normal" mode which would be 69 degrees, auto, dash vents "split" so not directly on your face. And maybe an "I'm Freezing" profile which would be full heat coming out of every vent possible, seat heater on full. You could then select a preset to be your default.

 

[beachmiles]

Verified with scanmytesla that my 2019 M3 on firmware revs the past couple months that the heater is still wanting to draw around 150 watts when it is ~74F degrees outside and my temp setpoint is 65F after driving for an hour. If I drop the temp down to LO my evaporator power usage stays the same around 120 watts and the heater turns off. If I set the temp to 67F and it's 70F outside the cabin heater draws closer to 500 watts.

So 150-500 watts being burned for no good reason for all the Tesla's around the world this adds up to a huge waste of energy.
I don't leave all the lights on in my house when I go run an errand. And Id rather not burn this power in my EV running on a battery as well. Maybe we need Greta Thunberg to remind Elon that we can always do better and to try and do everything we can to save every watt especially when there is low hanging fruit like this where a most likely easy software update could save a ton of juice across the world.