Does anyone else find it all a bit baffling? Usually I dont want the air conditioning on as it wastes fuel, and I tend to just want the normal blower on on a low setting. I'm not sure how to actually achieve that, though.

ECON

Think you’ll find modern ac systems only have a marginal effect on fuel economy.

With every car I’ve had with climate control I’ve set the temp at 20° ac on and auto and never had the need to touch the control again.

The benefit being at a comfortable temp, and no steamed up windows in the cooler months far outweigh the minimal amount of fuel used.

Also, most refrigerant gases have a small bit of lubricant in them. Thats needed for the seals etc in the a/c pump. Otherwise, the seals dry and the gas leaks. I've family members who found out the hard way in a Ducato. When getting it regassed, they were told to leave it on to stop leaks.

 

I'm another that has the a/c on permanently. I tried it with a/c off over 1000km and then a/c on for the same distance in a Leon and it made bugger all difference to the fuel economy 

Keeping it not steaming / misting up will need the systems very much working for the next few days in Edinburgh and through the winter.

It will have minimal affect on economy, and you can pre heat the cars interior & de-ice the glass while plugged into the mains before setting off when the weather turns cold.

Edited 28 October, 20232 yr by Rooted

2 hours ago, Hairy_Joe said:

Also, most refrigerant gases have a small bit of lubricant in them. Thats needed for the seals etc in the a/c pump. Otherwise, the seals dry and the gas leaks.

 

Not true on anything VAG for the last 15 years or so, when the AC is turned off (using the ECON setting on Climatronic) the pump still runs and circulates some refrigerant.

 

At this time of year the power consumed by the AC is negligible but when it was 40°c here for weeks on end it really knocked my fuel economy.

4 hours ago, mccririck said:

I dont want the air conditioning on as it wastes fuel

Really? I experimented on a stretch of quiet, dead flat road near my work. Switching the climate control on or off made a difference of 0.1mpg in favour of off, but on a base figure of 45mpg, call it 2%. I can make more of a difference by driving 5mph faster or lower.

If it is 40*oC ambient temp and you want the cars interior down to 20*oC or lower that does use energy, it has to and different from maybe 26*oC ambient and wanting the interior at 18*oc. 

Anyhow it is not just about cooling when you might use the AC, and when AC is available and not inhibited when it is near freezing or below.

4*oC with some cars and 2*oC with others and the AC is off. 

16 hours ago, Paws4Thot said:

Really? I experimented on a stretch of quiet, dead flat road near my work. Switching the climate control on or off made a difference of 0.1mpg in favour of off, but on a base figure of 45mpg, call it 2%. I can make more of a difference by driving 5mph faster or lower.

Can you check my maths as I make that 0.2% difference? (0.1÷45)x100 is 0.2%, I think.....

1 hour ago, Hairy_Joe said:

Can you check my maths as I make that 0.2% difference? (0.1÷45)x100 is 0.2%, I think.....

My decimal point slipped!

23 minutes ago, Paws4Thot said:

My decimal point slipped!

Sure if that's the worst that happens.....

Interesting test here - windows down vs A/C on full: 

 

And here's an updated test by the same guy:

 

https://www.youtube.com/watch?v=zMfqznarews

 

What this shows is that using the A/C to cool the cabin does use more fuel but using it to heat does not.

Edited 29 October, 20232 yr by mccririck

14 minutes ago, mccririck said:

And here's an updated test by the same guy:

 

https://www.youtube.com/watch?v=zMfqznarews

 

What this shows is that using the A/C to cool the cabin does use more fuel but using it to heat does not.

Technology has moved on a lot from 8 years ago.

12 minutes ago, Kenny R said:

Technology has moved on a lot from 8 years ago.

So now compressors for A/C use no power? The technology of compressors hasnt moved on that much. If you're using the A/C to cool the cabin it will be using power.

4 hours ago, mccririck said:

The technology of compressors hasnt moved on that much.

Older cars used fixed vane compressors and a clutch - so the compressor was either off or fully on - but for several years cars have used variable vane compressors which only use as much energy as needed.

 

In my book that's a significant move on in technology, and fuel saving.

'Climate Control etc,    & Air Conditioning.   Not just refrigeration.  

 

Many vehicles designed and built in Central or Eastern Europe are damn hopeless at demisting, and yet there are manufacturers very good at it and it does not even have to be expensive cars, even ones without AC. 

5 hours ago, mccririck said:

What this shows is that using the A/C to cool the cabin does use more fuel but using it to heat does not.

 

I have not watched the video but know that cannot be true, when you use AC for heating it first chills the incoming ambient air to close to zero°c to dehumidify it then uses the engine heat through the heater matrix to heat it up again to the desired temperature.

 

It will be using at a minimum twice the energy (hence fuel) than heating alone without AC.

50 minutes ago, PetrolDave said:

Older cars used fixed vane compressors and a clutch - so the compressor was either off or fully on - but for several years cars have used variable vane compressors which only use as much energy as needed.

 

The older ac clutching on and off to maintain the desired temperature only uses as much energy as is needed albeit not so efficiently.

 

The first ever car I had with AC was a Sierra, eventually it stopped cooling so I had it topped up by a Fred in a Shed, when he had done his stuff the AC compressor was cycling 'clutching) in and out and I said "thats not right, it has never done that before" to which he replied it is supposed to but when the refrigerant is low it has to work all the time to not even achieve the desired cooling.

 

The cooling and MPG improved significantly after the recharge. A lot of fuel gets wasted before you realise the AC needs the refrigerant topping up, I now have my own equipment and gas cylinder so have been checking and topping up as required as routine maintenance.

The OP has a 2023 Octavia iV PHEV.    Lovely to reminisce on the good old / bad old days but really he / she will find out soon enough what he needs to be using in Scotland this fine Winter to be comfortable and see out the windows.

2 hours ago, J.R. said:

 

I have not watched the video but know that cannot be true, when you use AC for heating it first chills the incoming ambient air to close to zero°c to dehumidify it then uses the engine heat through the heater matrix to heat it up again to the desired temperature.

 

It will be using at a minimum twice the energy (hence fuel) than heating alone without AC.

That's not what the video found. You should watch it.

I don't need to, I understand the first law of thermodynamics.

They are just transport.   Flash the cash and drive comfortably. 

8 hours ago, J.R. said:

I don't need to, I understand the first law of thermodynamics.

It could be the car he uses in the test doesn't use the A/C compressor for hot air. This is why I asked my original question - how can you make it just blow air without the A/C?

- go into the Clima Menu (physical button press or click/touch on the "Clima" text on the bottom of the screen)

- go into "Classic AC" sub-menu (see picture below)

- click the "AC" round button in the lower part of the screen - the one next to Air-recirculation and temperature-sync.
If it's green - AC is on, if it's white - AC is off.

When AC is Off, you'll also see a notification (AC OFF) in the bottom of the screen in the black square "Auto CLIMA" - the one next to the clock... see 2nd picture.

 

 

 

 

 

Edited 30 October, 20232 yr by SkOmk4