Use of Air Conditioner

[nm2003]

How often should you use your air conditioner?

The reason I ask is that I sometimes have a musty smell coming out of the vents after turning the air con on, after a week of not using it. The dealer had told me to always have it on, and you will not have such a smell coming from the unit.

I always thought that putting the air conditioner on causes additional engine wear and tear, as well as extra fuel consumption.

Should you have the air con unit on all the time?

Any thoughts?

[tlionhart]

you should use it all the time. However between econ and air con. Vary this. The components can cease up. Unlike older systems where you dont need to have them on, newer cars it's not a problem. Besides it doesn't use up as much fuel as everyone says. The smell will go eventually.

[ScottyUK]

People suggest 10% on fuel consumption. Dunno if it's true.

I never have it turned off and only occasionally have the compressor off (e.g. ECON/AC off etc).

I heard that the rubbers in the systems can dry out and cause problems if you have it off for extended periods

[nm2003]

How do you switch between econ and air con?

I thought you had it in "Auto" with had the air con on, or "Not Auto", which had the air con off. How do you get it into econ mode?

[ScottyUK]

Sorry. It's my fault for the confusion. On my S4 you had an ECON button which would still give air flow but not using the Air Conditioning compressor. On the B8 A4 it's simply a button that says AC that does the same.

Having the compressor on does use fuel and add a bit of load to the engine. However Audi are cunning enough that it cuts the compressor when you're on full throttle so you get maximum power when needed.

From the manual :


Deactivating the AC mode

– Press the button.

Activating the AC mode

– Press the button again.
In the AC mode, the air cooling system is switched on and the heating and ventilation are regulated automatically.

[Plife]

I have not turned the ac off since I got the car even when using heat. A previous car when I did not use AC during the winter and when I started using it the smell was horrendous. Was advised to always keep on, as apparantly bacteria builds when it is not being used.

[nm2003]

I have not turned the ac off since I got the car even when using heat. A previous car when I did not use AC during the winter and when I started using it the smell was horrendous. Was advised to always keep on, as apparantly bacteria builds when it is not being used.

Looks like I will be keeping the AC on all the time then.

One question I have is durability of the AC over time if always left on. Anyone with an older A4 care to comment on any reliability of AC units if left on all the time?

[Black Phantom]

Keep these posts coming, I need to know this stuff. The heating system is a bit of a mystery to me.:confused:

[ScottyUK]

Looks like I will be keeping the AC on all the time then.

One question I have is durability of the AC over time if always left on. Anyone with an older A4 care to comment on any reliability of AC units if left on all the time?

I doubt you'll still have it by the time the compressor expires ;)

[A1287210]

Done some testing and found that A/C is about 2 mpg better without A/C on. i.e. 2 mpg from about 50 mpg.

I suppose it depends upon what engine you have and how much you want that extra 2 mpg. I tend to turn if it off in the sort of weather we have been having recently. just beware:

If you close your eyes and they ache it is likely to be the a/c or it could be tiredness.... more likely to be long journeys with the A/C on


my wife is an optician ....... looking forward to the day when we can buy her a B8 S line :biglaugh::biglaugh::biglaugh::Blush::Blush2:

[msmith4000]

Have 2000 (W) A3 1.9 TDI 110 SE it has 129,000 on the clock and my climate control still works perfectly. I cant speak for the previous owner but since I have had it when it had 95,000 on the clock I have the climate control on all the time but only switch the compressor on (using the button with the frost symbol) when I need cool air of if my windows are misting up. Living in scotland there is not much days in the year I have my compressor on, in fact I have it on more in winter when you jump in the car with wet clothes and the windows steam up! I maybe have the compressor on for 30 / 40 days of the year, about 1,200 miles.

Compressors I think a fairly hardy devices but like any mechanical equipment can fail, just your bad luck if you get one that breaks early. Mine is ok and the compressors in the industrial air con units feeding the computer room at my work has gone 9 years switched on 34/7 before a compressor finally failed in one of the out door units.

In contrast my girlfriend just bought a second had A3 1.8S 77,000, test drove it, switched on climate control cold air comes out working OK, bought it drove off the forcourt stopped at the junction at the end of the road and hear this clacking noise like something was hitting one of the fans. The noise went away when you revved the engine hence we did not notice it on the test drive. Took it straight back to the dealer, naturally, by this time I had switched of the climate control and when we stopped it was OK. The dealer bless them could not be apologetic enough and repaired the faulty compressor. Not a cheap one to replace a broken compressor I believe, £400 - £500 fitted?

Least we know why the previous owners got rid of such a clean A3 LOL :beerchug:

Its nice having the luxury of the climate control so enjoy it its there to be used so there is something to be said to having it on all the time, so I say just use it as you want to use it, if it breaks it breaks thats the cost of having these luxuries!

That withsaid at a cost of £450 to replace a compressor that is perhapes why there is an off switch for these devices and I dont fancy a £450 bill so I will just do what I do now and switch off the compressor when I am not using it and risk the broken seals.