My aircon has worked perfectly all summer long with fairly regular use. Now it's winter I like to use it to clear the screen quicker but I'm not sure if it's kicking in. There's no apparent rev change, nor is there a smell after you turn it off like there normally is.

Clearly it's hard to tell but are there any diagnosis methods?

A lot of systems wont work when it's below 5'c incase of freezing the evaporator up. I know that is the case on the older octavias. But without getting it plugged in to vagcom or getting the pressure tested it could be anything at all

Odds on it's just low temperature, but if it's been more than 2 years since it was last done, a regas won't do any harm, and will show if there's a leak...

Once fixed...Don't turn it off..ever

It will last longer, prevent bacteria building up and demists the interior quicker

The above post is fine, but be aware that you will have increased fuel consumption,

You should run your aircon for at least 5 minutes a week no matter what, the gas contains a lubricant that prevents the seals drying out and also helps prevent bacteria build-up.

If the seals go, it will potentially cost a fortune to find the leak and fix it.

I would either get it. Necked using bag com or go to a reputable specialist who can test for leaks and advise how much gas you have remaining.

No..thats a myth...the increase is so minimal..you will struggle to see it

A lot of systems wont work when it's below 5'c incase of freezing the evaporator up. I know that is the case on the older octavias. But without getting it plugged in to vagcom or getting the pressure tested it could be anything at all

 

+1, It is explained in the handbook I believe too!

If you do go for a regas - http://www.hotukdeals.com/deals/air-con-recharge-29-99-ats-euromaster-24-99-with-voucher-1701369

No..thats a myth...the increase is so minimal..you will struggle to see it

I can confirm this, based on practical experimentation using instantaneous mpg mode and switching in and out of Climatronic Econ at steady speed on a flat road.

 

It was true once but back then switching aircon on demanded about 10bhp to run the compressor.

Ok, not wishing to start a free for all, can you explain to me why on the instantaneous fuel consumption on SWMBO Fabia I see a jump of about 5mpg.

Also, speaking with 2 companies I use (one of which is a well known, well established company) they both agree that fuel consumption increases due to the load drawn by the aircon compressor.

Not trying to start an argument, just repeating what 2 separate experts told me.

Seems obvious to me that fuel consumption increases, but by how much I couldn't say  (it's her car and I don't care that much as she buys the fuel!).  Cooling stuff takes lots of energy, just like heating stuff does.  All that energy comes from long-dead dinosaurs in your fuel tank. I'm not aware of any fundamental improvements in compressor technology which would render 'newer' systems much less greedy than 'older' ones?

I thought I read that the Fabia system constantly 'trickles' the refrigerant round even when switched off, so arguments about seals drying out from disuse are irrelevant?

I'm not having an argument about it either. I leave mine on all the time

Why?

Because........

A. It has never made any difference to my overall fuel consumption

B. Turning it off can cause bacterial build up in the unit

C. It aids in condensation removal

Chris I'd disagree with A, agree with B and wonder why you have so much condensation that C becomes relevant (have you got a sunroof with blocked drain pipes, blocked pollen filter or leaking rear doors...?)

Everyone gets condensation when left out in high humidity cold nights. I have no leaks or blocked drain pipes or a sunroof or blocked pollen filter...lol

We will have to disagree on A

I've never seen any increased fuel consumption as a result of the air on. Modern units don't affect like the older ones did

Thanks for the response.

I'd have to disagree I believe it reduces fuel consumption and when I ran it in the summer I could feel a slight but only sight power loss. Don't see the point in using extra fuel when I don't need to as since I've done the door seals, the car doesn't feel damp inside.

Can't seem to remember if last winter when it was cold if it worked then or not because I've got this feeling it won't start in the cold anyway.

Doesn't the compressor turn all the time, therefore the parasitic loss (like a blower) is there all the time, as chris says leave it on !

Doesn't the compressor turn all the time, therefore the parasitic loss (like a blower) is there all the time, as chris says leave it on !

Yeah the mk1 vrs compressor is turning all the time due to it not having a clutch mech I believe.

I leave my system on auto, which is essentially air con on all the time.

The car just does its own thing and all I ever do is alter the temperature.

I like it warm and she likes it cool so dual climate is ideal for us.

If I was bothered about MPG then I wouldn't have got a S3 in place of my old Mark 1

Fab vRS

Compressor is always pumping on a fab, it is a variable displacement unit so just reverts to min when the ac is off so it is always circulating the gas as long as there is some , this is why it is important to ensure that some oil is added when the system is regassed and why we see so many seized compressors. The nut in the middle of the pully should turn with the pully , if it doesn't then it has seized and the freewheeling safety clutch has come in to save it throwing the drive belt off.

I rest my Chappaties!!  

Ok, not wishing to start a free for all, can you explain to me why on the instantaneous fuel consumption on SWMBO Fabia I see a jump of about 5mpg.

Also, speaking with 2 companies I use (one of which is a well known, well established company) they both agree that fuel consumption increases due to the load drawn by the aircon compressor.

Not trying to start an argument, just repeating what 2 separate experts told me.

I was reading an article about a 1960s Rolls Royce over breakfast. The subject car had the optional aircon on it. The compressor filled a space in the boot about 2'by1'by1'. Do you still say that the technology hasn't evolved even though that compressor is bigger than an entire 1.9TDi?

Some people clearly do think that!! LOL

I'm not having an argument about it either. I leave mine on all the time

Why?

Because........

A. It has never made any difference to my overall fuel consumption

B. Turning it off can cause bacterial build up in the unit

C. It aids in condensation removal

 

Consider this, if you never used the chiller, you would not have a build up of bacteria in the cabin inlet tract, it is the collected atmospheric moisture going stale in the cabin inlet tract due to it sweating out of the air on the (cold) chiller evaporator that causes the build up of moisture. One way to avoid that is to, after periods of A/C use, switch to ECON and demand cold air, doing that will strip the "cold" out of the evaporator and that will avoid it collecting moisture when the car has stopped.

 

Personally, I think that most people that do not notice an increase in fuel usage when A/C is enabled are also the people that buy fuel when ever they need it and pay the going rate, but strangely buy cars that are known to have good MPG. I see the change in fuel use in my wife's Polo 1.4 when someone has accidentally bumped into the AUTO switch when it has been left in ECON, but then I also notice the increased fuel usage in my S4 when the A/C is left enabled, I have not worked out which type of compressor is fitted to it though, so I really should run it for 10 minutes every week - just in case.

 

We are all individuals, but there are some true facts out there and some mistruths.

As said...I NEVER turn it off, never will and will always advise others to do the same

It makes more sense that turning it off IMO

Sorry chris, I'm with run4mo on this one.......