Types of aircon and how they work ?

[Nick_H]

Some questions and pre-concieved ideas I have on Aircon .....

The very first time I had aircon was on a 1986 Celica Supra Mk2. You turned the aircon on and set the temp. Their were no temp markers on the gauge. I believe the compressor ran all the time ? and their was a pretty heavy hit on fuel.

The current Fabia had Climatic. This is how I believe it works. You tuen it on and the compressor runs all the time ? You can set the temp to a specific temp via an analogue dial. The fan stays at a constant selected speed but the aircon varies the temp. The aircon may not be able to maintain the temp without intervention of the fan speed. Their is a hit on fuel consumption ( 1.416v ) or appears so as the trip comp shows a decrease in mileage when aircon is on.

The soon to be picked up Octavia had Climatronic. This is electronic and will vary the fan / temp to control the temp in the cabin.

1) Will the compressor stay on all the time. If not then how does it cope with de misting in the winter ?

2) What is the economy setting and what use does it perform ?

3) Should the aircon be left on at all times ?

4) Will I notice a performance / increased fuel economy by using it all the time ? 1.9Tdi.

5) How often does everyone else use their aircon ?

Cheers !

[Guinness]

1) No, the climate control will engage the compressor as and when required to maintain the temperature you set. In the winter, I would specifically turn the air con on, and the temperature up a litte to de-mist.

2) Switches off the compressor entirely, hence uses no extra fuel

3) Apart from the hit on your fuel, it wont do any harm at all - in fact, it's less likely to leak if you do as the sealed systems are self-lubricating. If you didn't use it all winter, over time, there's a risk of rubber seals drying out and becoming ineffective

4) Can't speak from experience on this, but I've found that the performance drop is noticeable on 1.6 or smaller - but 1.9 tdi i would expect you wont notice

5) Sounds like a stupid answer, but only when I need it! Better for my wallet (and the environment) if I switch it to ECO. Although if I'm conscious I haven't used it for a week or so, I'll give it a few hours blast for the reason mentioned in (3)

... I'm no expert, by the way. Sure someone will be along soon with better skoda-specific advice!

[vimto2000]

Well not sure completey how it works....but I do remember a long thread about the operation of the Aircon system.

As to how I operate mine...always on and left on 22C unless the temp is really hot out side, or really cold! Got to say its one of the best features! Just set it and forget it, unlike the normal air con where you have to keep adjusting it.

[Tech1e]

Just to add some factual information the compressor on the Octavia 2 has NO clutch and thus is operational all the time.

[cng]

Following on from the last message. How then does the ECON button function ? Presumably there is less drag from the ever spinning compressor when switched to ECON mode as maybe the refigerant doesn't circulate ?

Anyway I have the dual zone climatronic and I find it seems to take too much notice of the outside temperature. For example it could be 15oC outside but sunny and the cabin is warm from the sun and feels a lot warmer than 15oC but with the temp dial set at 19oC say I will get warm air and therefore have to turn the dial down lower. The opposite seems to occur on hot but overcast days , I will then get the colder air even though the cabin felt the same inside. I will have to stick a thermometer inside the car to check . It might just be me, or do others find the same?

[Tech1e]

When Econ is switched on the fans stop and the compressor load is reduced down to 2%.

The load of the compressor is altered internally via a duty cycle from the a/c control unit, but it doesn't drop below 2% so the system is allways circulating.

[VRickS]

I have noticed a drop in power when the compressor is running in AUTO, but put it in ECON and the car feels much faster. I noticed the same on my SEAT Ibiza 130TDi. My last car (mazda RX-8) has the ECU set to drop off the compressor when you put your foot flat to the floor, to not lose any power when you really wanted it.

I wonder whether there's a VAGCOM setting you could use to produce the same effect? Well if Mazda can do it......

Rick

[Tech1e]

Im pretty sure it does it allready, it varies the compressor load due to many factors.

[dstev2000]

Vectra VVT does it as well, dob the accelerator and the A/C briefly cuts out.

Roll on electric compressors, much less hassle than the open drive jobbies, totally sealed, variable speed, better efficiency and no clutch to drop off - marvellous!

[slider]

I keep air con switch on almost always and set to 19 deg.

I have experimented a bit in the past and never noticed any drop in power or fuel consumption.

[dstev2000]

I keep mine on ECON unless I really need it, I carry enough cr@p around as it is.

[mluton]

Leave in AUTO, set it to 21 degrees. Sorted.