[fkyang]

Hi all,
I always manually turn off A/C before turn off the engine.
When I turn it off, I can feel A/C stopped working.

However, the next time I start the engine, I can feel A/C is on automatically (even A/C still disappear on the middle small display).

Does anybody knows why? I don't want it on automatically.

Thank you

[HighlandPete]

Originally Posted by fkyang

Hi all,
I always manually turn off A/C before turn off the engine.
When I turn it off, I can feel A/C stopped working.

However, the next time I start the engine, I can feel A/C is on automatically (even A/C still disappear on the middle small display).

Does anybody knows why? I don't want it on automatically.

Thank you

It is likely the demands you are asking for, due to your settings, require A/C to achieve the target.

My understanding, latest models use A/C "when necessary", as part of the Climate Control function.

Out of interest, what are your settings for heating/cooling?

[mofomat]

Originally Posted by fkyang

Hi all,
I always manually turn off A/C before turn off the engine.
When I turn it off, I can feel A/C stopped working.

However, the next time I start the engine, I can feel A/C is on automatically (even A/C still disappear on the middle small display).

Does anybody knows why? I don't want it on automatically.

Thank you

There are two elements to consider. The climate control function can be on without the A/C selected. The A/C function "boosts" the climate control and also dehumidifies. It's my guess that by default, when you turn the car back on, the climate control comes on, just without the "A/C" element.

You seem to be conflating "A/C" & "climate control" without fully understanding they are two different functions.

[fkyang]

Originally Posted by mofomat

There are two elements to consider. The climate control function can be on without the A/C selected. The A/C function "boosts" the climate control and also dehumidifies. It's my guess that by default, when you turn the car back on, the climate control comes on, just without the "A/C" element.

You seem to be conflating "A/C" & "climate control" without fully understanding they are two different functions.

Thanks for sharing!
I think my purpose is to turn off the air-con "compressor" before stop the engine and also when next time I start the car, I don't want compressor to work in the first few minutes.

Originally I do that in old car by pressing physical button "A/C" to force stop the "compressor".

So that means in new car (say, G20) this will be control by the car automatically even I switch A/C off via my touch screen when I start the car.

[fkyang]

Originally Posted by HighlandPete

It is likely the demands you are asking for, due to your settings, require A/C to achieve the target.

My understanding, latest models use A/C "when necessary", as part of the Climate Control function.

Out of interest, what are your settings for heating/cooling?

My settings are most by default.
Just set temperature to 22 degree C.
Recently we have around 28 degree C ~ 33 degree C outside which like you said, A/C will on automatically to cool down the vehicle.

[HighlandPete]

Originally Posted by fkyang

I think my purpose is to turn off the air-con "compressor" before stop the engine and also when next time I start the car, I don't want compressor to work in the first few minutes.

Can I ask why you want A/C off in those situations? Is for some personal or an obscure technical reason?

Just trying to grasp the reason, or necessity to even touch it.

[hamera]

Originally Posted by HighlandPete

Can I ask why you want A/C off in those situations? Is for some personal or an obscure technical reason?

Just trying to grasp the reason, or necessity to even touch it.

I'm guessing he doesn't want that extra load on the engine at start up?

Originally Posted by fkyang

Hi all,
I always manually turn off A/C before turn off the engine.
When I turn it off, I can feel A/C stopped working.

However, the next time I start the engine, I can feel A/C is on automatically (even A/C still disappear on the middle small display).

Does anybody knows why? I don't want it on automatically.

Thank you

I'm messing with the A/C on/off quite often. It stays off when I switch it off manually. It's definitely not automatically back on after restarting in my case.

[Liquid_Ice]

It stays off for me when I turn it off. But you have to go into the climate menu to turn it on/off. On US cars, there is a button on the dash that says "Menu A/C", and if you press that button a menu pops up on the screen where you can turn off the A/C.

When I do that, it stays off - I actually turn it off in the winter time. I know it stays off because now that is has become warmer, I was wondering why the car wasn't cooling off when I turned the temperature down recently and had to turn the A/C back on.

You can see the button here in this dash picture, it is next to the recirculate and "Max A/C" buttons:

If you use this iDrive 7 simulator, you can try pressing the "Menu A/C" button and this should be very similar to what pops up - assuming you have iDrive 6. It is probably a little different on iDrive 7.

http://bmwpkod.com/Media/Default/sta...ENU/index.html

You press Menu A/C then Heating/Ventilation then uncheck the A/C box.

[fkyang]

Originally Posted by HighlandPete

Can I ask why you want A/C off in those situations? Is for some personal or an obscure technical reason?

Just trying to grasp the reason, or necessity to even touch it.

Originally Posted by HighlandPete

Can I ask why you want A/C off in those situations? Is for some personal or an obscure technical reason?

Just trying to grasp the reason, or necessity to even touch it.

Hi
In Taiwan, the weather is super humid. So we always turn off a/c and keep only fans running for a while before turn off air conditioner, no matter in the car or at home.
This will prevent water drop to appear inside the machine which might cause mold.

The next day we try to let fans work for a while to blow out bad air inside the machine before turn on the a/c.

I think not everybody will do this but I have children who are more sensitive to the air quality, this is why I need to do it.

And for old car, yes to reduce engine loading but for new car like G20, compressor actually will delay for few seconds after engine starts so this won't be a problem.

[fkyang]

Originally Posted by Liquid_Ice

It stays off for me when I turn it off. But you have to go into the climate menu to turn it on/off. On US cars, there is a button on the dash that says "Menu A/C", and if you press that button a menu pops up on the screen where you can turn off the A/C.

When I do that, it stays off - I actually turn it off in the winter time. I know it stays off because now that is has become warmer, I was wondering why the car wasn't cooling off when I turned the temperature down recently and had to turn the A/C back on.

You can see the button here in this dash picture, it is next to the recirculate and "Max A/C" buttons: [img]https://s.aolcdn.com/dims-global/dim...nter-stack.jpg[/img]

If you use this iDrive 7 simulator, you can try pressing the "Menu A/C" button and this should be very similar to what pops up - assuming you have iDrive 7. It is probably a little different on iDrive 7.

http://bmwpkod.com/Media/Default/sta...ENU/index.html

You press Menu A/C then Heating/Ventilation then uncheck the A/C box.

Yes this is exactly what I did.
Turning a/c off is not the problem, but my problem is the next time when I start the car, even a/c indicator is off, I can feel it(compressor) is working and temperature is changing.

[HighlandPete]

Originally Posted by fkyang

Hi
In Taiwan, the weather is super humid. So we always turn off a/c and keep only fans running for a while before turn off air conditioner, no matter in the car or at home.
This will prevent water drop to appear inside the machine which might cause mold.

The next day we try to let fans work for a while to blow out bad air inside the machine before turn on the a/c.

I think not everybody will do this but I have children who are more sensitive to the air quality, this is why I need to do it.

Understand your reasoning.

Is the G20 that sensitive to humidity?

I'm also in a rather humid atmosphere for a large part of the year. (You should see the rust on my brakes after a couple of nights). But to be honest, I've found switching off A/C is more trouble than it is worth.

I know when running my E39, to dry the system, it took over 5 miles (ten minutes running) to do so. If it was really humid, the car would start misting before getting home. If not dried over enough distance, as soon as I started again there would be misting, showing it was still wet inside. Leave A/C on, no issues with misting, or smells from the system.

My F11, A/C is on all year, no smells, no issues in almost 8-years use.

[HighlandPete]

Originally Posted by fkyang

The next day we try to let fans work for a while to blow out bad air inside the machine before turn on the a/c.

Originally Posted by fkyang

Turning a/c off is not the problem, but my problem is the next time when I start the car, even a/c indicator is off, I can feel it(compressor) is working and temperature is changing.

Does not having the A/C starting immediately, make any difference to the initial air purging/flow? Surely any 'bad air' comes out the vents, with or without A/C? It is the same air after all.

[fkyang]

Originally Posted by HighlandPete

Does not having the A/C starting immediately, make any difference to the initial air purging/flow? Surely any 'bad air' comes out the vents, with or without A/C? It is the same air after all.

Good point, combine your experience of F11 and I can still keep windows open for a while with ac running next day. I think I will just leave the ac on all the time.

[hkleyman]

Originally Posted by Liquid_Ice

It stays off for me when I turn it off. But you have to go into the climate menu to turn it on/off. On US cars, there is a button on the dash that says "Menu A/C", and if you press that button a menu pops up on the screen where you can turn off the A/C.

When I do that, it stays off - I actually turn it off in the winter time. I know it stays off because now that is has become warmer, I was wondering why the car wasn't cooling off when I turned the temperature down recently and had to turn the A/C back on.

You can see the button here in this dash picture, it is next to the recirculate and "Max A/C" buttons:

If you use this iDrive 7 simulator, you can try pressing the "Menu A/C" button and this should be very similar to what pops up - assuming you have iDrive 6. It is probably a little different on iDrive 7.

http://bmwpkod.com/Media/Default/sta...ENU/index.html

You press Menu A/C then Heating/Ventilation then uncheck the A/C box.

I had been shutting mine off in the winter and then discovered that it would randomly turn on here and there. The display would not indicate it but I knew it was running. After doing some research there as a failsafe that will run the compressor to keep it oiled and all of the seals in tact. Apparently it's not good to have it not run during winter consistently as it could shorten the life.

[del82]

Originally Posted by hkleyman

I had been shutting mine off in the winter and then discovered that it would randomly turn on here and there. The display would not indicate it but I knew it was running. After doing some research there as a failsafe that will run the compressor to keep it oiled and all of the seals in tact. Apparently it's not good to have it not run during winter consistently as it could shorten the life.

Yep this is my understanding as well that keeping it on all year round is better than turning it off.

I used to turn it off during winter but for the past 2 years have it one all year round and have no issues. If anything I've noticed less misting overnight as well.

I also understand that car AC units are different to building ones in that the mouldy water issue isn't an issue in modern car AC units unless left for weeks on end and especially if cleaned regularly.

[hkleyman]

Originally Posted by del82

Yep this is my understanding as well that keeping it on all year round is better than turning it off.

I used to turn it off during winter but for the past 2 years have it one all year round and have no issues. If anything I've noticed less misting overnight as well.

I also understand that car AC units are different to building ones in that the mouldy water issue isn't an issue in modern car AC units unless left for weeks on end and especially if cleaned regularly.

Totally. If it's gross humid out I may let the coils dry a bit in the garage with AC disabled but that's because I'm extremely OCD. I'm going to leave it alone in the winter going forward.

[doctorttt]

Is it a best practice to turn off the AC manually before shutting off the engine?

If I remote start and I previously manually turned off the AC, will the vehicle automatically turn on the AC according to the user defined temperature?

It is very hot right now in the east coast.

[fkyang]

Originally Posted by doctorttt

Is it a best practice to turn off the AC manually before shutting off the engine?

If I remote start and I previously manually turned off the AC, will the vehicle automatically turn on the AC according to the user defined temperature?

It is very hot right now in the east coast.

I believe it still works since according to what I reported, compressor turn on next time even I turned A/C off before engine off last time.