Feature Request - Eco-Mode Air Conditioning

[Sam T]

All Models:

Eco-Mode - Reduce consumption of the Air conditioner by about half.

Heater Toggle - Turn off the heater for the air conditioner to draw fresh air instead.

Recirculation timer - turn off recirculation after 15mins to avoid high condensation.

After using the Polestar 2 for three months I’m extremely surprised Tesla didn’t already incorporate these highly valuable features.

Likely uses:

In hot or mild weather after reaching the desired temperature or humidity level toggling eco-mode will enable the user more control over the internal environment and air-con consumption.

On a hot day setting the thermostat to 20C will eventually activate the heater core. Disabling this will force the already hot air from outside (or current temp air from inside) to maintain the desired temperature thus reducing air-con consumption.

Recirculation timer is useful in situations where the user would like fresh air to enter the cabin to reduce humidity levels in eco-power mode or to increase oxygen levels.


Please reply if you’d like these features in the next software update.

 

[DownshiftDre]

The heat pump (assuming you have a more modern Tesla) is a variable speed system. As you set the system to AUTO at the desired temperature the heat pump control system will run to effieciently get the cabin to your desired temperature (heat or cool) quickly and then will run at the minimum speed needed to maintain that setting as economically feasible.

 

[Sam T]

yea I know - that’s the problem.

 

[Sam T]

Running the heat pump is the opposite to efficiency- when the outside is already hot

 

[Sam T]

It’s a very well documented problem going back at least 3 years:

You just need to search google for “how do I turn off the heater on a Tesla”

Can you stop climate control from heating??

I was wondering if there is a way to disable heating when using AUTO climate.. Let's say that I set my auto climate to 70 degrees and after a while, we feel that 70 is too cold and we set the temperature to 74 degrees with outside temperatures in the 90's. Now, instead of just stopping to cool...

teslamotorsclub.com

Climate control

Is it better to use auto climate control or should I adjust it manually to get a better range? I noticed that if I set same cabin temperature what is outside even then car will sometimes turn on AC.

teslamotorsclub.com

There are numerous people asking the same question.

And similar responses from possible employees or ambassadors of Tesla: The computer knows best.

This complete disregard for customer feedback is abysmal and may even be contributing to the downward slope of the stock price.

Cars have been around for long enough and people are smart enough to figure out if they want the heater core engaged or not. They don’t always need a computer to make decisions for them.

It’s evident the heater core being engaged on a 100F day is a waste of energy and I’ve personally estimated the heater to consume between 500-1000 watts.

Not to mention the AC unit consumes anywhere between 1000-7000watts - that’s between 5-50% of the total consumption.

That’s right - HALF of the energy is going to the AC on an extremely hot day. Why? Because the AC unit was designed to reduce consumption in ONE scenario - when its cold out.

Customers are circumnavigating this on hot days by turning the ac on low and adjusting the fan to suite the needs of the cabin - which completely nullifies the design concept of the “most efficient masterpiece” heat/ac system.

Adding a low power mode and heater toggle at the very least will not only fix the problem on hot days, but will extend the range by up to 50%.

 

[Sam T]

Also documented here:

cabin heater coming on when only cooling desired

teslamotorsclub.com

 

[DownshiftDre]

Running the heat pump is the opposite to efficiency- when the outside is already hot

I would like to explain further since maybe your response here makes me believe you may not know what a heat pump is nor how heat transfer works. There is no “heater core” nor “air-con” in the traditional sense in a Tesla. A modern Tesla doesn’t have a seperate heater and a seperate air conditioning compressor. It has one thing only and that is the heat pump. This serves the purpose of “heater” and “air-con” in one system.

A heat pumps job is move heat away from one area and to another area. A heat pump can heat an area or cool in area. Everything has heat in it, even a -20F day. On a cold day, the heat pump absorbs the heat from the outside air and rejects the heat to the cabin, heating the cabin. On a hot day, the heat pump absorbs the heat away from the cabin and rejects it to the outside air, cooling the cabin.

Therefore a variable speed heat pump will run at its minimum optimum speed once your cabin is at desired setpoint (heat or cool). No need for Eco Mode.

 

[Supcom]

I would like to explain further since maybe your response here makes me believe you may not know what a heat pump is nor how heat transfer works. There is no “heater core” nor “air-con” in the traditional sense in a Tesla. A modern Tesla doesn’t have a seperate heater and a seperate air conditioning compressor. It has one thing only and that is the heat pump. This serves the purpose of “heater” and “air-con” in one system.

A heat pumps job is move heat away from one area and to another area. A heat pump can heat an area or cool in area. Everything has heat in it, even a -20F day. On a cold day, the heat pump absorbs the heat from the outside air and rejects the heat to the cabin, heating the cabin. On a hot day, the heat pump absorbs the heat away from the cabin and rejects it to the outside air, cooling the cabin.

Therefore a variable speed heat pump will run at its minimum optimum speed once your cabin is at desired setpoint (heat or cool). No need for Eco Mode.

For those who aren't familiar with the system, this youtube video is a fascinating introduction to the system:

 

[Sam T]

Everything has heat in it, even a -20F day

This is not correct.

A modern Tesla doesn’t have a seperate heater and a seperate air conditioning compressor. It has one thing only and that is the heat pump

Incorrect.

For those who aren't familiar with the system, this youtube video is a fascinating introduction to the system:

This video is misleading and gives the impression warm air is contained within cold air - this is incorrect.

The HVAC system stands for Heating ventilation and air conditioning.
“HVAC is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space.”

The various technologies include compressed refrigerant, fans, suction, a compressor, condenser, etc.

A HVAC unit is not a “heat pump” blowing or sucking heat or cold air from one part to another. It’s more complex than that.

At the end of the day, the Polestar 2 HVAC system has an eco-mode (using about half the energy) a heater toggle and uses about 10% of the battery and around 0.3-2kw.

The Tesla Y HVAC unit is reported to use anywhere between 0.8-7kw and customers complain about the missing functions. Customers claim the unit uses up to 50% of the battery. This has been my experience also.

It would be good to have some support for these ideas instead of people just repeating random things from YouTube videos.

 

[UncleCreepy]

You won't get any support because you are not making sense. Since you have already made it clear that you are resistant to education, I am not going to waste my time rephrasing what others have tried to explain to you.
'nuff said

 

[Zuikkis]

We have a heat pump heating our home. It works just fine with -15C outside and +20C inside.

It makes the outside air slightly colder and then pumps that difference into inside air. It's just like "A/C" cooling but in opposite direction.

Big benefit of heat pump is that it typically uses only 1000W of electricity to generate 3000W of heat.

In the summer the exact same device works for cooling.

And that's how it really is with modern Teslas. There is no separate cooling and heating, it's just the same heat pump that can be used both ways.

Earlier cars (pre-2019?) had normal A/C for cooling, and resistive heat element for heating.

 

[SidetrackedSue]

I won't get into the intricacies of heat pumps. I will say that there are days when I would be happy with my car bringing in 20*C air from outside and not bothering to decide on the humidity level that air should be by conditioning it first. I can't do that on my tesla without opening a window (with the resulting loss of range due to aerodynamics.)

In the winter, if the sun is beating down on the front of the car, I get annoyed when the car suddenly blows cold air on me in order to bring the temperature of the cabin down to whatever number I selected (usually 21*C in winter.) I'm happy with the sun on the glass bringing the temp up to 23*C and don't care if the car runs a little 'warm' while traveling in that direction. I just don't want the car to drop below 21*C. But that isn't an option in my car.

Then we get to humidity levels and defrosting and cold feet. The tesla insists on me relying on the computer to know everything and not being able to adjust things the way that leave me most comfortable. Worse, as a passenger, my feet get cold, partly from the cold air coming down off the windshield onto my legs, this is not as noticeable when driving because the steering column deflects the cold air away from my legs and my feet are moving more due to using the pedals. But I can't select the warm air to be split between my legs and face without forcing the driver's air flow to change. As well, in the winter in my old car, I'd use defrost and floor heat to keep the windshield clear and my feet warm. When I put on defrost, I lose control over the air flow to my body as everything seems to be diverted to the windshield. Worse, the fan goes on high, which has the effect of drying out my eyes, making driving even more uncomfortable and in my case requiring me to take eyes off the road to deal with the fan speed as the voice command doesn't work for me over the roar of the fan.

Finally, in cases where the range is at risk, turning off the HVAC entirely and only using heated seats is fine for winter for front passengers but isn't an option if you are driving with children in child seats in the back.

If this was shoulder season and I only wanted to cool off the cabin using outside air and not the a/c to preserve range, that is not an option like it was on my Prius.

All of this is part of the 'tesla knows best' attitude that ties into a lot of the discomfort people have with the car (like not having control over following distance or the speed TACC is set to changing because the car decides that's best.)

 

[Big Earl]

I won't get into the intricacies of heat pumps. I will say that there are days when I would be happy with my car bringing in 20*C air from outside and not bothering to decide on the humidity level that air should be by conditioning it first. I can't do that on my tesla without opening a window (with the resulting loss of range due to aerodynamics.)

You can do that. Set the temp to LO, then turn off the A/C compressor and choose your fan speed and vents. This will do fresh air only.

In the winter, if the sun is beating down on the front of the car, I get annoyed when the car suddenly blows cold air on me in order to bring the temperature of the cabin down to whatever number I selected (usually 21*C in winter.) I'm happy with the sun on the glass bringing the temp up to 23*C and don't care if the car runs a little 'warm' while traveling in that direction. I just don't want the car to drop below 21*C. But that isn't an option in my car.

Turn off A/C and it won't do that. You don't have to run automatic all the time - cases like this are where manual control is nice.

Then we get to humidity levels and defrosting and cold feet. The tesla insists on me relying on the computer to know everything and not being able to adjust things the way that leave me most comfortable. Worse, as a passenger, my feet get cold, partly from the cold air coming down off the windshield onto my legs, this is not as noticeable when driving because the steering column deflects the cold air away from my legs and my feet are moving more due to using the pedals. But I can't select the warm air to be split between my legs and face without forcing the driver's air flow to change. As well, in the winter in my old car, I'd use defrost and floor heat to keep the windshield clear and my feet warm. When I put on defrost, I lose control over the air flow to my body as everything seems to be diverted to the windshield. Worse, the fan goes on high, which has the effect of drying out my eyes, making driving even more uncomfortable and in my case requiring me to take eyes off the road to deal with the fan speed as the voice command doesn't work for me over the roar of the fan.

Select the appropriate vents to direct air where you want it. Don't use the windshield defrost icon - instead, use the icon with the person and the up arrow. This will direct air to the windshield without activating max defog/defrost, leaving you in full control. You can do windshield + feet without the face vents if you want.

Finally, in cases where the range is at risk, turning off the HVAC entirely and only using heated seats is fine for winter for front passengers but isn't an option if you are driving with children in child seats in the back.

I don't think there's anything you're going to do about this in any car. If you're low on range and can't spare the electrons for heat, use a blanket. I don't know of any car that gives you the option to do rear climate control without also using the front climate control.

If this was shoulder season and I only wanted to cool off the cabin using outside air and not the a/c to preserve range, that is not an option like it was on my Prius.

Sure you can. Set the temp to LO, then turn off the A/C button, select your fan speed and preferred vents. Voila - fan-only.

All of this is part of the 'tesla knows best' attitude that ties into a lot of the discomfort people have with the car (like not having control over following distance or the speed TACC is set to changing because the car decides that's best.)

I've seen a lot of complaints from people who don't understand how the system works or what the various functions do. This takes some experimentation to figure out.

 

[SidetrackedSue]

I don't think there's anything you're going to do about this in any car. If you're low on range and can't spare the electrons for heat, use a blanket. I don't know of any car that gives you the option to do rear climate control without also using the front climate control.

As soon as there is rear-heat for kids in car seats you have the heat pump on therefore lose the range extending. This wasn't as much a complaint as a warning to parents to be careful with their range. Turning off the heating system makes a huge difference when one is very tight on range - the day we had to do it, we luckily didn't have the kids, the seat heaters kept us warm enough and I grabbed a blanket I use for the kids in their seats for my legs. It was a 10% range boost with no downside except for having to cycle the defrost by hand from time to time.

 

[Sam T]

You won't get any support because you are not making sense. Since you have already made it clear that you are resistant to education, I am not going to waste my time rephrasing what others have tried to explain to you.
'nuff said

To be completely honest Unclecreepy, I’m not sure anyone would pay attention to what Uncle Creepy has to say. I certainly won’t give you the light of day. Maybe try creating a username which doesn’t have sexual undertones. ‘Nuff said.

 

[Sam T]

There is no separate cooling and heating, it's just the same heat pump that can be used both ways

You all seem to think a HVAC unit is a heat pump??

“A heat exchanger in an HVAC system uses conduction to transfer heat. This is the traveling of heat energy from one molecule to another using direct contact with the temperature source. HVAC heat exchangers will either heat or cool the air with conduction, but they need the proper medium from which to get the energy”

 

[Big Earl]

Did you know that a heat pump system contains heat exchangers? Several of them, in fact.

 

[Zuikkis]

You all seem to think a HVAC unit is a heat pump??

Yes, because that's what it is. Here's a diagram. You may choose to ignore this, I'm not going any further in this discussion.

It shows both cooling and heating modes. As you see the operation is reversed, there is no way it could somehow do both at the same time as you suggested.

Tesla system is slightly different than above. It's really water-to-water heat pump, not air-to-air what's pictured above. This allows heat to be taken from multiple sources. It uses the heat from battery and motors for example. In MCU3 cars even the MCU is water cooled, so that heat can be used elsewhere.

 

[DownshiftDre]

You all seem to think a HVAC unit is a heat pump??

“A heat exchanger in an HVAC system uses conduction to transfer heat. This is the traveling of heat energy from one molecule to another using direct contact with the temperature source. HVAC heat exchangers will either heat or cool the air with conduction, but they need the proper medium from which to get the energy”

Let get technical and not quote a commercial/residential general HVAC website.

These systems are all considered part of a thermal management system. (TMS). High end thermal management systems understand that all mediums above absolute zero contain energy. You are playing and hiding behind the words of cooling and heating. It is all one thing. It is energy transfer that can be extracted from source and moved to a sink. A heat pump system is one modality to achieve TMS. For EV, it works well because the pump runs well on available electric power and there are many systems that need a variety of different temperatures sometimes at the same time that heat pumps and clever heat exchanger architecture can provide.

By the way, I looked up your Polestar 2 you keep referencing. We shouldn’t take it serious until every Polestar 2 comes with a heat pump. It looks like heat pumps are an upgrade option. Not standard. This makes me believe that their TMS was not built from the ground up to support a heat pump system. Which means efficiency is likely lower and that there are compromises made, including an “Eco Mode”. Whatever that means in modern day TMS.

The kWh numbers you are quoting in terms of power dont mean anything either without knowing the heat rejection.

TMS are actually graded in terms of COP. Coefficient of Performance. Power rejected divided by power input.

Usually this is done at a system level and not component level. One cannot compare two heat pumps at just power input numbers and deduce one is twice better without knowing the heat rejection number as well. You really think Tesla is off by a factor of 2?

 

[Big Earl]

Yes, because that's what it is. Here's a diagram. You may choose to ignore this, I'm not going any further in this discussion.

View attachment 1021675

It shows both cooling and heating modes. As you see the operation is reversed, there is no way it could somehow do both at the same time as you suggested.

Tesla system is slightly different than above. It's really water-to-water heat pump, not air-to-air what's pictured above. This allows heat to be taken from multiple sources. It uses the heat from battery and motors for example. In MCU3 cars even the MCU is water cooled, so that heat can be used elsewhere.

The Tesla heat pump actually can do both at the same time. It has a second "outdoor coil," mounted inline with the indoor coil. This allows it to cool and dehumidify the air, then reheat it to maintain a comfortable temperature. This is particularly important in cool, humid weather and in the rain. In this mode, which is controlled by a temp and humidity sensor located in the rear view mirror housing, it functions like a typical home dehumidifier. This example is a bit oversimplified - the Tesla system has more than a dozen modes and is quite complex. It's one of the most efficient HVAC systems available in a car.