Don't want heater on, want vent

[Park2670]

You’re correct that in moderate temperature, high humidity conditions, a system that prioritizes comfort over efficiency will cool the air to dehumidify it, then reheat it so as to not overcool the cabin. Teslas do this.

Vehicles with a heat toggle/button will sacrifice occupant comfort in exchange for better range - at least when the driver disables heating. They’ll ramp the compressor down to maintain a comfortable temperature, but in doing so, they don’t dehumidify as well due to the higher evaporator temperature. The evaporator surface temperature must be below the dew point in order for it to dehumidify.

Thanks. Ive lived here all my life and never needed to dehumidify my air.

Thought it was such a weird thing when I was installing my home Ecobee and it asked if I wanted it to dehumidify the air. "Now why would I do that?"

 

[Candleflame]

Sorry, there must be something missing in our discussion.

You could have heat, or ac, or only outside air. If you used the Fan Only option, that 26° air would come inside the vehicle at 26°. No AC compressor running.

Also, I live in a desert, so fan only was a feasible option when humidity is in the low teens.

yes. but if you just cool the air thats not air conditioning, thats cooling...

 

[Big Earl]

yes. but if you just cool the air thats not air conditioning, thats cooling...

While "air conditioning" can mean a number of things, in the context of a car with an A/C button, "air conditioning" typically means active cooling by means of a refrigerant compressor. The A/C button is what enables/disables the refrigerant compressor.

 

[Park2670]

While "air conditioning" can mean a number of things, in the context of a car with an A/C button, "air conditioning" typically means active cooling by means of a refrigerant compressor. The A/C button is what enables/disables the refrigerant compressor.

Thank you, that is what I was missing in this back and forth.

Funny to think this thread started back in 2018 and it's still not a feature in the car.

 

[Candleflame]

While "air conditioning" can mean a number of things, in the context of a car with an A/C button, "air conditioning" typically means active cooling by means of a refrigerant compressor. The A/C button is what enables/disables the refrigerant compressor.

you can technically set the temp to LO and then just use the vent speed. but that just doesnt feel particularly comfortable.

 

[Big Earl]

Thank you, that is what I was missing in this back and forth.

Funny to think this thread started back in 2018 and it's still not a feature in the car.

If the "feature" you're requesting is vent with no heat, turn off the A/C button and set the temp to LO. This will provide fan only, with no heat and no active cooling.

 

[bay74]

If the "feature" you're requesting is vent with no heat, turn off the A/C button and set the temp to LO. This will provide fan only, with no heat and no active cooling.

But don't forget that after the above steps you then have to again switch off the AC because the stupid system turns the AC button on again when you drag the temperature control to LO. Then when you want cooling you have to set the temperature to something reasonable and activate the AC and probably turn on recirculate. Yes I do this but it's awful. A simple two-set-point range or a heater-off button would resolve the issue.

Yeah it's funny that this thread started in 2018 and is still going.

 

[beachmiles]

Yep my resistive cabin heater is still cranking when I only want cooling AC which royally sucks. How in the world is this still an issue??

The small bright side is that I've noticed that the cabin heater has been not coming on as much during the midday hours here in the desert when I set the temp to 70F as long as the outside temp is above 74F degrees.

But as it gets later in the day closer to sunset the cabin heater almost immediately starts getting used even if it's 80F outside with my 70F setpoint.

I read somewhere in a forum that somebody took their car in 4 times for this issue and only on the 4th visit did they evidently fixed it by replacing the evaporator temperature sensor. I unfortunately only took my car in for this issue a out 3 times and now it's out of warranty so will try to replace the sensor myself.

 

[cali8484]

Yep my resistive cabin heater is still cranking when I only want cooling AC which royally sucks. How in the world is this still an issue??

Did you ever put in the CAN bus switch?

 

[beachmiles]

Did you ever put in the CAN bus switch?

I stopped trying to work on that as disabling the CAN bus to the heater did not stop the AC from continuing to cool the car below my temp setpoint so I just set the temp to LO and use lower fan speeds to regulate the temp.

 

[beachmiles]

Cabin heater still coming on in the evening with it being 74F outside 71 inside with 71 degree setpoint in version 2023.27.6. During the day with it 80F outside and a setpoint of 71 the cabin heater stayed off at least. So the closer the outdoor temp is to your setpoint the more likely the cabin heater will be used. I instantly felt the hot air on the vent towards my face which royally sucks. Freaking insane Tesla has not fixed this wasteful and uncomfortable bug.