On 4/5/2018 at 01:08, norsko said:

One question; Why is it important that the AC is on at winter?

Yes I am aware of the air drying effect from AC, BUT the AC compressor has an electric clutch that just engage the compressor when needed to save fuel.

In Norway with really cold winters we never need any cooling, we need heat. So I dont understand why the AC compressor should kick in at any time?

And if it doesnt, it has no effect?

 

There is no clutch on the AC compressors on these cars, they run constantly - Same with the Superb II and quite likely the Octavia II. 

I think the minimum "load" is about 2%, which occurs when you switch it off.

Just out of interest...I have only starting using Auto Climate control in my Mark 3 Octavia estate.

Seems to work well...

Current temp set set to 20C.

What do you set it too in the summer when its really hot ? 

Ie if you set it to LO does it cool the car inside to a certain temp relevant to the outside one ?

 

Thanks.

2 minutes ago, speedy9 said:

Just out of interest...I have only starting using Auto Climate control in my Mark 3 Octavia estate.

Seems to work well...

Current temp set set to 20C.

What do you set it too in the summer when its really hot ? 

Ie if you set it to LO does it cool the car inside to a certain temp relevant to the outside one ?

 

Thanks.

You leave it at 20°C and it cools the car to that temperature. Lo just blasts cold air with no end in sight until you set a temperature. 

5 minutes ago, SC03OTT said:

You leave it at 20°C and it cools the car to that temperature. Lo just blasts cold air with no end in sight until you set a temperature. 

 

+1  leave it on 20 ac on and on auto 24/7 365

Edited 11 February, 20206 yr by Kenny R

How does 20C feel in the car when its 30C outside  !!!! Does that feel cool with the aircon on then ?

Just thought it would have to be a lot lower ???

 

7 minutes ago, speedy9 said:

How does 20C feel in the car when its 30C outside  !!!! Does that feel cool with the aircon on then ?

Just thought it would have to be a lot lower ???

 

 

It will feel 10° cooler than it is outside

 

Point taken 🙂

 

11 minutes ago, speedy9 said:

How does 20C feel in the car when its 30C outside  !!!! Does that feel cool with the aircon on then ?

Just thought it would have to be a lot lower ???

 

I usually keep mine around 17-18C during summer (20C feels too warm for me at summer) and when it’s really really hot i set to LO so it gets cold then raise to 16,5-17C 

 

I keep my side at 21 C all year round and SWMBO moves her side between 18 and 20 C (depending on whether she's having a 'hot flush'), always on Dual Auto (and with recirc on when we're behind a stinky old style diesel).

When we had the 30+ temps last summer, I turned the AC up to 24. Sounds perverse, but even 24 feels comfortably cool when it's so hot outside. Normally it's on 22 ±1°C

5 hours ago, speedy9 said:

Just out of interest...I have only starting using Auto Climate control in my Mark 3 Octavia estate.

Seems to work well...

Current temp set set to 20C.

What do you set it too in the summer when its really hot ? 

Ie if you set it to LO does it cool the car inside to a certain temp relevant to the outside one ?

You will probably want to turn the temperature up slightly in the summer. 20 °C all year round will feel warm in the winter and cold in the summer.

I lost my AC profile option  now fan symbol is missing (low, medium,high) after MIB 2.5 and VC upgrade. Any way to fix this.

 

One interesting point nobody has mentioned (I think) is that the compressor chucks out nice dry air. During the summer, when it's hot, I'll run the a/c for obvious reasons (usually just on screen and vents at about 19°). In spring and autumn I usually have it at 18/19° but with a/c off.

 

Of course, in winter, it doesn't make sense to have a/c on, but I always have it on and set at 20°. When the air is damp, and the interior has wet feet or whatever, having the a/c on prevents any damp.

 

Another thing is to get a nice air freshener jar thing, and some silica moisture absorbing bags. These, combined with the a/c, mean the car stays fresh and dry all year round. I hate damp in cars.

I have my a/c on all the time. Humiditiy control in winter is the main reason, another is that a/c compressor, valves and seals tend to live much longer if you do not keep airco off for several months in winter.

Note that I have had to change coding on the airco control unit to make sure humidity is controlled as well as in my previous Skodas. The default settings are so eco-friendly, that the AC is automaticlaly off as soon as internal temperature can be controlled with (often damp) air from the outside. So by default, temperature control is good, but humidity control is inadequate.

 

3 hours ago, dieselV6 said:

I have my a/c on all the time. Humiditiy control in winter is the main reason, another is that a/c compressor, valves and seals tend to live much longer if you do not keep airco off for several months in winter.

Note that I have had to change coding on the airco control unit to make sure humidity is controlled as well as in my previous Skodas. The default settings are so eco-friendly, that the AC is automaticlaly off as soon as internal temperature can be controlled with (often damp) air from the outside. So by default, temperature control is good, but humidity control is inadequate.

 

 

Do you have any more info on this? Sounds like something I'd want to do!

3 hours ago, dieselV6 said:

a/c compressor, valves and seals tend to live much longer if you do not keep airco off for several months in winter.

 The default settings are so eco-friendly, that the AC is automaticlaly off as soon as internal temperature can be controlled with (often damp) air from the outside

 

Incorrect, your AC compressor is a non clutch type whose modulating valve circulates refrigerant 100% of the time even when you believe it is switched off albeit at a reduced duty cycle.

....Bear in mind I have 2 cars, and Roomie does not want to keep the ac going unless it's on (older style compressor), so my remark on seals, valves and compressor still applies. But for both cars, including my Mk3 OCtavia vRS, it's the humidity that forces year round use of a/c for me. Neither car is garaged, and if you forget using airco  in winter for a while, both would start to feel/smell like a moldy damp sofa after a month or so. 

 

Regarding HVAC coding, I think there are 2 options, "use in humid countries" or "humidity control/" or the like (I think byte 14 x8 and x4), and the other which I found made more difference was byte 13 "compressor on when not cooling" because then obviously it dries out incoming air. I have actually disabled the byte 14 x8 option and switched to x4 which also does something on demisting (don't remember VCDS description exactly, just have my coding noted), for me the byte 13 change made all the difference I needed. Note it does increase fuel consumption, but only in line with what previous Skoda's did, i.e. if the AC is switched on, the compressor keeps the evaporator at near freezing, that's all.

 

Edited 9 December, 20241 yr by dieselV6

I will look for that byte on my vehicle, I have never liked the idea of freezing air only to then warm it up.

 

I bet your Roomster does not have that option, have a look and see if it has a clutch or the shear plate type pulley, the power lead to the electro-magnetic clutch will be clear to see.

 

I switch my AC off (although I know its not 100% off) often in winter for fuel economy switching it on when I need to clear misting and humidity which is more often than not, if your setting was available to me and I selected it I think it would pretty much stop the demisting working unless I wanted to do it with cold air.

 

Have you tried both settings? What did you experience?

1 hour ago, J.R. said:

I will look for that byte on my vehicle, I have never liked the idea of freezing air only to then warm it up.

 

I bet your Roomster does not have that option, have a look and see if it has a clutch or the shear plate type pulley, the power lead to the electro-magnetic clutch will be clear to see.

 

I switch my AC off (although I know its not 100% off) often in winter for fuel economy switching it on when I need to clear misting and humidity which is more often than not, if your setting was available to me and I selected it I think it would pretty much stop the demisting working unless I wanted to do it with cold air.

 

Have you tried both settings? What did you experience?

 

My 2012 Roomster does have compressor with integrated magnetic clutch, mine is 5N0820803E. There were lots of compressors on the Roomster, including scroll ones, it seemed like a parts dump model in this respect. I think Denso ones are scroll, and Sanden ones are clutch, but I may be wrong.

On earlier models, eg mk1 Octavia, the clutch and the coil pack were visibly separate to the compressor, this was not the case anymore on models with integrated clutch,  but as far as I am aware, mine still a magnetic clutch model.

It feels like one when you press ac button (sudden jerk on the belt), and a quick look at autodoc shows quite a few magnetic clutch replacement plates for this particular compressor part number, absent from other compressor models.

 

The Roomster's compressor runs all the time when a/c button is on, unless freezing/overpressure etc. The Mk3 Octavia one does not pressurize coolant circuit unless HVAC controller demands cold air, at least in the default coding (compressor not enabled when not cooling).

 

Freezing cold air to get water out then heating it back up again is pretty much like every compressor type dehumidifier works, and so keeping the compressor running will result in dry air being fed into cabin.

Not sure why it would stop demisting, if anything, cold air with water removed heated back up/mixed with hot air = way drier air, so if anything, demisting would be even faster. 

 

All I can say on the topic is that with the byte 13 option enabled (compressor on when not cooling), my car is way drier, or rather acceptably dry when used infrequently, and also when used on a long trip in rainy/very wet weather at outside temperature around cabin temperature. This was very much not the case until I have enabled that "compressor on when not cooling" option. Even with compressor on, it still modulates the output on the vRS, so the only difference is that evaporator is always cold and collecting water from incoming air, if it's cold outside, there's not that much heat transfer occuring anyway. I guess the compressor also shuts down around freezing.

 

Edited 9 December, 20241 yr by dieselV6

Understood, I think I got your previous explanation backwards in my head, I thought you had disabled the option.

 

It gives me another thing to look at and tweak if need be in VCDS.

Hi

Can anyone support to get the menu back in climate control menu.

 

Thank you @dieselV6, I'll have a look at what I can do on OBD11 (I remember seeing humidity something), otherwise I'll drop my mate with VCDS a visit. I think my car will be alright as I have several silica bags stashed in the rear door pockets/boot/glove box/spare wheel well/under seats, but I do try and keep ti as dry as I can. I do a lot of mountain biking, so having wet muddy gear in the car for the drive home is never nice...

 

The increase in fuel consumption would concern me, but a) this time of year the consumption is crap driving cold around town and b) when the car does get warm on longer journeys, I have A/C on anyway. I tink it's a decent trade off. As the Octavia's compressor is always on anyway, it shouldn't really give me any issues re wear, should it?

 

I really must give Occy a proper run soon - I try my best to take it one junction on the motorway and put my foot down once its warm, but that's not enough. All this constant cold town driving can't be good for the engine.

I can't believe I am only just realising now that my 2018 Octavia, bought in 2019, can do all this!

I always struggled with demisting, only pressing AUTO to speed defog my windows then turning it off again!

I too, always thought the AC should be just turned on in hot weather!

I must have a look and adjust mine to Auto and AC on  always..