I noticed that if I turn on the air ventilation WITHOUT having the air condition ON (but temp setting is set to cold) , the air coming inside the cabin is cold, much colder than the outside temperature. Almost like the aircon is always on. I haven't given much attention to it since I got a replacement car while the car was at service. The car was the same model, same engine (tsi 95ps), and it seemed to me that the engine was much more pumpy (I even thought that it was the 110ps version, but it was not). So I am starting to think if it is possible that the aircon is -wrongly- always on, even if the button to turn it on is not pressed, or is this a normal phenomenon, that somehow the air gets colder when running from outside throiuh the ventilation canals.

 

Any thoughts?

It's not always on with ours. We have the automatic control and there's an A/C on off button. You can certainly feel when its on or not.

 

That said remember that just air blowing on you will feel cooler than still air. That's why you can buy fans for your house, too. So maybe it's just that?

I don't have auto clima, I have basic air con that starts by a button.

I know about the still/moving air (I am a physicist :)), and having the air blowing in scale 1 where the air speed is definetely low is not enough to produce this effect. I will have it checked of course. Thanks for replying.

I also have the basic A/C system and with mine I have noticed:-

 

The A/C will automatically turn itself on when you turn the fan on and:-

 

You have the air pointing at the screen during the winter / cold weather.

You have the air pointing at the footwells during the summer / hot weather.

 

The A/C also works all the time but without the A/C button on / yellow warning light on it is only running at about 5-6 %.

So yes it can feel colder than you would expect some times.

 

Thanks AG Falco

Mine is a manual aircon. I never turn off the aircon. Leaving them off for a long period can allow mould to grow and start smelling resulting in having to have the aircon 'sanitized'. I've not had problems with aircon in any of my cars since I had a Ford Escort in the 90s.

15 hours ago, TerFar said:

Mine is a manual aircon. I never turn off the aircon. Leaving them off for a long period can allow mould to grow and start smelling resulting in having to have the aircon 'sanitized'. I've not had problems with aircon in any of my cars since I had a Ford Escort in the 90s.

 

Using it continuously will not stop mould growth, using it continuously and stopping the car while the cabin air box is still cold will draw in more moisture, and that will cause mould growth which needs killed using an AC "bomb".

Also, using it continuously doesn't put stress on the engine and affect the overall performance?

Well 30 years of always running aircon is suffifient proof that it works for me. I turn the temp control down when it's hot and up when it's cold. 

Just now, TerFar said:

Well 30 years of always running aircon is suffifient proof that it works for me. I turn the temp control down when it's hot and up when it's cold. 

 

It does not make your statement correct though, think about how/why/where the mould is coming from and what conditions promote its survival or growth.

1 minute ago, kosnik said:

Also, using it continuously doesn't put stress on the engine and affect the overall performance?

Insignificant in cool/cold weather, probably does in hot weather. But if you're concerned about it, why have aircon: it's there for comfort. 

1 minute ago, rum4mo said:

 

It does not make your statement correct though, think about how/why/where the mould is coming from and what conditions promote its survival or growth.

So in cool/cold weather, how does turning it off stop mold? 

3 minutes ago, kosnik said:

Also, using it continuously doesn't put stress on the engine and affect the overall performance?

 

Not true, any chilling effort used will come at the expense of engine output and extra fuel usage, even although it will be normally quite low, there is no such thing as free chilling, energy will always be required.

16 hours ago, AGFalco said:

I also have the basic A/C system and with mine I have noticed:-

 

The A/C will automatically turn itself on when you turn the fan on and:-

 

You have the air pointing at the screen during the winter / cold weather.

You have the air pointing at the footwells during the summer / hot weather.

 

 

Do you know this from seeing the AC switch light up or from some other way?

2 minutes ago, J.R. said:

Do you know this from seeing the AC switch light up or from some other way?

Exactly what I was going to ask!

 

also, having the manual switch for the fan  to 0 , I guess  that it will keep the aircon off in any case right?

1 minute ago, TerFar said:

So in cool/cold weather, how does turning it off stop mold? 

 

Turning it off is not stopping the build up of mould, it is how you use it that either causes the build up of mould or dose not, for instance, as I live further up the UK, I use/need AC for cabin comfort, than maybe you do, but when I use it I normally disable the chiller a few miles before reaching my destination, doing that is boring but it dries out the cabin air box and returns its temperature to local ambient, so no chance of moisture gathering and causing/feeding mould.

3 minutes ago, kosnik said:

Snip   ------ Snip

 

also, having the manual switch for the fan  to 0 , I guess  that it will keep the aircon off in any case right?

 

Yes.

Edited 25 June, 20205 yr by rum4mo

Just now, kosnik said:

Exactly what I was going to ask!

 

also, having the manual switch for the fan  to 0 , I guess  that it will keep the aircon off in any case right?

The only 'automatic' action I see in the system is if you lower the temperature control down to the lowest section, it switches on recirculation and speeds up the fan slightly. Converse when you turn the control up above the lowest setting. But with the aircon ON, the blue on light glows continuously. 

6 minutes ago, kosnik said:

Exactly what I was going to ask!

 

also, having the manual switch for the fan  to 0 , I guess  that it will keep the aircon off in any case right?

I never have the fan off, so I'm not sure though I'll check when I go out later today. 

Regarding the always on but at 5%. I guess that's possible. I think VAG now use variable displacement pumps on some models and it's entirely possible that Fabia is one. So in this case it never switches off completely just compresses much less than at full tilt.

 

With the automatic control, if you select front demist MAX setting (a separate button) then if AC is off it is switched on (there's the letters A/C in the display). If you switch off MAX again, then A/C switches off. If however you use Auto to switch off MAX, then A/C stays on even when cold. Can't say about just selecting the 'screen' direction as we never use it.

Yes, all current and previous generation VW Group cars are fitted with variable displacement compressors as part of a "greening" move, it makes a lot of sense whichever way you look at it, compressor is always turning and so passing enough oil mist through the system to minimise leaks at seals and plastic piping, even when chilling the displacement will be aiming to vary to achieve the correct delivery of  chilling to the incoming air, so less need for wasted chilling effort being trimmed out by blending in  engine waste heat, just more efficient  more of the time.

Edited 26 June, 20205 yr by rum4mo
Corrected "oi" to "oil" and "or" to "of".

6 hours ago, J.R. said:

Do you know this from seeing the AC switch light up

 

Yes.

 

And you can feel it as well.

 

Thanks AG Falco

6 hours ago, TerFar said:

I never have the fan off, so I'm not sure though I'll check when I go out later today. 

I can confirm that the aircon light goes out when the fan is switched off suggesting that the aircon does go off. But as it was 34 degC today, I wasn't keen on experimenting to see if it definitely turned off. 😉