*sigh* Rookie Question about A/C ... why is it running when parked in my garage?

[MikeRTX]

First, Cabin Overheat is set to come on at approx. 100 degrees.

Second, I come out to my garage to get something and notice the car is on and the A/C is blasting (it's 106 outside). The A/C is set to 70, like I left it when parked. But I sure didn't want it to keep the car at 70 while I wasn't using it! So I was forced to turn off the climate control through the app.

WHY did it do this??? I expect the Cabin Oveheat Protection to keep it from getting a million degrees in there, but NOT to keep the A/C going and running down my battery!

What did I do wrong?

 

[Tam]

First, Cabin Overheat is set to come on at approx. 100 degrees.

Second, I come out to my garage to get something and notice the car is on and the A/C is blasting (it's 106 outside). The A/C is set to 70, like I left it when parked. But I sure didn't want it to keep the car at 70 while I wasn't using it! So I was forced to turn off the climate control through the app.

WHY did it do this??? I expect the Cabin Oveheat Protection to keep it from getting a million degrees in there, but NOT to keep the A/C going and running down my battery!

What did I do wrong?

When the car is off, it would cool down to the Cabin Overheat temperature of 100F maximum even though you set it at 70F.

However, when you are near your car with your key/fob, the car is no longer off; it's awakened, so the overheat protection mode is off, but your AC is now on at your set temperature of 70F.

To avoid that, you must remember to manually turn off your AC when leaving your car.

 

[brkaus]

When the car is off, it would cool down to the Cabin Overheat temperature of 100F maximum even though you set it at 70F.

However, when you are near your car with your key/fob, the car is no longer off; it's awakened, so the overheat protection mode is off, but your AC is now on at your set temperature of 70F.

To avoid that, you must remember to manually turn off your AC when leaving your car.

Really? I've never had the AC come on when I was close with the paired phone key.

I've only noticed the AC on 70 (not the 100 cabin overheat) is if I have turned it on in the app, left a door ajar, put the AC in "keep, camp, or dog mode". I supposed if the seat sensor was bad, the car may stay on too.

Were the mirrors folded?

Was it really 70 in the car? It will still definitely run the AC occasionally to cool the battery or for cabin overheat.

 

[Benito1283]

When the car is off, it would cool down to the Cabin Overheat temperature of 100F maximum even though you set it at 70F.

However, when you are near your car with your key/fob, the car is no longer off; it's awakened, so the overheat protection mode is off, but your AC is now on at your set temperature of 70F.

To avoid that, you must remember to manually turn off your AC when leaving your car.

The car absolutely will not wake up when you're just near it with a phone/fob. You've got to either open the app or enter the car to wake it up.

If the AC was on because of Cabin Overheat Protection, it was doing what it's supposed to (cooling off the car). I don't think the last temp you had it set to would affect COP behavior.

The only other reason the AC would be on if you're not in the car is if you either went into the app and turned on climate, or selected "keep" or "dog mode" before you left the car.

It's also possible you were just hearing the fan to either dry out the AC ducts (mold prevention) or the car was just cooling the battery down before going to sleep.

I personally think COP in a garage is a total waste.

 

[turns2stone]

First, Cabin Overheat is set to come on at approx. 100 degrees.

Second, I come out to my garage to get something and notice the car is on and the A/C is blasting (it's 106 outside). The A/C is set to 70, like I left it when parked. But I sure didn't want it to keep the car at 70 while I wasn't using it! So I was forced to turn off the climate control through the app.

WHY did it do this??? I expect the Cabin Oveheat Protection to keep it from getting a million degrees in there, but NOT to keep the A/C going and running down my battery!

What did I do wrong?

Are you sure it's the A/C 'on', or are you just hearing your car spinning fans in the garage?

 

[ucmndd]

Were all of your doors fully closed?

 

[FFR6288]

It's pointless to use COP in a garage that is hotter than the COP temperature. The car is just pumping the internal heat to the exterior, which in the garage just makes the car's environment hotter. So the car works even harder to cool the interior. It's a feedback loop that just wastes energy.

I can't use COP at home in the summer, because my garage is seldom less than 100.

 

[ucmndd]

It's pointless to use COP in a garage that is hotter than the COP temperature. The car is just pumping the internal heat to the exterior, which in the garage just makes the car's environment hotter. So the car works even harder to cool the interior. It's a feedback loop that just wastes energy.

I can't use COP at home in the summer, because my garage is seldom less than 100.

Surely your garage has ridge venting or other heat exchange with the outside, ya? It’s not a closed system.

Not that I’m advocating against turning off COP. It’s a silly waste of energy.

 

[brkaus]

Surely your garage has ridge venting or other heat exchange with the outside, ya? It’s not a closed system.

Not that I’m advocating against turning off COP. It’s a silly waste of energy.

My garage is a non-vented sheet rock finished room. Of course, air leaks around the garage doors. But it gets above 100 late afternoon.

 

[FFR6288]

Surely your garage has ridge venting or other heat exchange with the outside, ya? It’s not a closed system.

Not that I’m advocating against turning off COP. It’s a silly waste of energy.

No, it really is closed. And stop calling me Shirley!

 

[rpiotro]

Surely your garage has ridge venting or other heat exchange with the outside, ya? It’s not a closed system....

Not always. When my home was built there was no venting. I had a ridge vent added when my roofing was redone about 15 years ago. It actually made little difference.

 

[MikeRTX]

The car absolutely will not wake up when you're just near it with a phone/fob. You've got to either open the app or enter the car to wake it up.

If the AC was on because of Cabin Overheat Protection, it was doing what it's supposed to (cooling off the car). I don't think the last temp you had it set to would affect COP behavior.

The only other reason the AC would be on if you're not in the car is if you either went into the app and turned on climate, or selected "keep" or "dog mode" before you left the car.

It's also possible you were just hearing the fan to either dry out the AC ducts (mold prevention) or the car was just cooling the battery down before going to sleep.

I personally think COP in a garage is a total waste.

I was messing around in the climate part of the app and changed the temp, so maybe I inadvertently turned the A/C on. I know it hasn't been running while parked before, so surely that's it.

BTW, the cabin temp was about 78, so it wasn't the COP, which was set at the default of 100 degrees.

Are you sure it's the A/C 'on', or are you just hearing your car spinning fans in the garage?

Nah, it was on and actively cooling the interior.

I must have done something to turn on the A/C when I was messing around in the app. It hasn't happened again, so I blame me.

I appreciate all the responses, though. You guys are a great resource.

 

[Benito1283]

BTW, the cabin temp was about 78, so it wasn't the COP, which was set at the default of 100 degrees.

COP is set to come *on* at 100 degrees. I’m not sure what temp it cools the cabin to. But it sounds like you kinda figured it out.

 

[Candleflame]

autodry for the ac system

 

[brkaus]

I must have done something to turn on the A/C when I was messing around in the app. It hasn't happened again, so I blame me.

You're probably correct. I think if you mess with the temp settings, it will assume you want to turn on the system and do it for you.

 

[citivolus]

Just to be clear, is the guidance here that one need not turn off the climate control when exiting the car since it will turn itself off after you exit, and it will remain off (even if you are nearby with the paired phone as key in your pocket) until you open a car door?

 

[brkaus]

Just to be clear, is the guidance here that one need not turn off the climate control when exiting the car since it will turn itself off after you exit, and it will remain off (even if you are nearby with the paired phone as key in your pocket) until you open a car door?

That is correct. It will do some magic stuff (circulate outside air to dry the coils and have overheat prevention) but it should not be cooling to the set target unless something is wrong.

 

[Candleflame]

Just to be clear, is the guidance here that one need not turn off the climate control when exiting the car since it will turn itself off after you exit, and it will remain off (even if you are nearby with the paired phone as key in your pocket) until you open a car door?

in the past the AC used to immediately switch off after closing the doors - in 2019 they patched in that the fan would continue running to dry the AC.

 

[blackT3$!@]

I can't use COP at home in the summer, because my garage is seldom less than 100.

Leave all your windows open and cool your garage down with your Tesla!