Ok, thought I'd ask this directly as I can't find it in a search.

Coming home last night, decided to give the A/C a bit of exercise and use it to take the edge off some of the misting on my rear windows. All worked wonderfully until I turned it off.......and then the car turned into a turkish steam bath. All the windows steamed up within minutes to the point where I could hardly see out. I ended up turning the A/C on again just to stop me from crashing.

Normally the car hardly steams up at all without the A/C on unless I've been to the gym or there's a couple of us in the car and it's cold/ raining, and even then it's only a bit.

But this was mad. It's the longest I've had the A/C on since getting the car in Jan and it left me regretting it. The air was not set to recirculate or anything...all fresh.

Any ideas why the A/C would cause this? It's almost like it was storing the moisture it was extracting only to release it when the A/C was disengaged.

Chris.

There are a lot of posts on this. From memory, some of things said are that: (in no particular order)

To clear it quickly, use recirculate and A/C (with some heat).

Use A/C all the time, don't use recirculate all the time

Leave vents open at night (screen and foot)

Switch A/C off a couple of miles before stopping

Make sure you don't have any leaks in footwells etc.

Make sure filters etc in A/C are not clogged up

And probably a couple of others IIRC.

I find that my little 8V does this after parking for a short while, but TBH I'm not an expert and it seems somewhat random as to when it does or doesn't do that. My friend's "posh" BMW was a nightmare on a motorway drive recently, irrespective of what he did with the controls and me "squegeeing" and wiping the inside of the windscreen. I'm surprised you've not found a lot from doing a search, but it might be a case of trial and error as to what works with yours?

Just my view as I know nothing about cars except what I learn on here

Mo

Some cars with climate control state in the manual that you should use air con all the time as it keeps the system working properly through regular use and it keeps the windows clear.

I've also heard elsewhere that you should turn off the A/C a couple of minutes before you switch off the car.

God knows which is the right approach!

Some cars with climate control state in the manual that you should use air con all the time as it keeps the system working properly through regular use and it keeps the windows clear.

I notice a drop in mid-range acceleration on the motorway with the air-con. Also, on a straight and level stretch of road, just see how much difference the air-con makes to fuel consumption indicated on the trip computer.

When air is passe over the cold heat exchanger, in an AC unit, moisure in the air condenses onto the coils, like condensation on a cold beer (mmmm....beer!). This dries the air, hence it cleares misted windows considerably faster. If you turn AC off, you are still passing the ventilation air over the now wet heat exchanger, evaporating moisture back into the air, which you then blow over your relatively cool windows, and making them mist up like glasses in a sauna.

Some cars are worse than others. Our old A6 never misted, no matter what, but Vauxhalls and our truck seem pretty bad for it.

Best methods I've found are

1) run AC all the time - eats fuel though.

2) Don't run AC, unless its really hot.

3) If you turn AC on, don't turn it off until you finish your journey, but expect misty windows at the start of the next journey.

Phil

Ahh.....so that's why. I did have it on for a prolonged period I must admit so there may have been a lot of moisture there hence it steamed up like hell when I turned the A/C off.

Where is the heat exchanger located? In the dash? If so, then could it cause wet carpets if it had too much moisture on it or does it drain outside the car somewhere?

AFAIK it goes out through a drainpipe, so unlikely to cause wet carpets. Wet carpets might cause misting though LOL. There's a test to run A/C at max till freezing cold and then make sure that you can see a puddle under the car later, to see whether the drainpipe is draining efficiently or might be blocked. Dunno how much water might be needed to condensate before such evidence of puddle though, so could be perfect wrong conclusion.

I know nothing

Mo

I used to leave my air con on all the time in the Fabia (although it switched itself off below 5 deg C IIRC) and never noticed any gains in performance or economy when it was off. Never had a problem with the windows misting up either

Chris

I used to leave my air con on all the time in the Fabia (although it switched itself off below 5 deg C IIRC) and never noticed any gains in performance or economy when it was off. Never had a problem with the windows misting up either

Chris

When what was 5 degrees?

When what was 5 degrees?

Sorry - should have made that clear! Outside temp below 5 deg C....

Chris

Sorry - should have made that clear! Outside temp below 5 deg C....

Chris

Ta. Does that mean you can't use the A/C to unmist the windows below 5? Or can you just turn it back on again?

When what was 5 degrees?

External temp. When it drops to 5c the A/C compressor is cutout. The light may still indicate the a/c working though.

Ta. Does that mean you can't use the A/C to unmist the windows below 5? Or can you just turn it back on again?

Nope, it switches off to stop internal freezing in the compressor IIRC so you're on your own in terms of window demisting!

Chris

I used to leave my air con on all the time in the Fabia (although it switched itself off below 5 deg C IIRC) and never noticed any gains in performance or economy when it was off. Never had a problem with the windows misting up either

Chris

See, I hate people who have no misting I'm wondering (serious question) whether you clean your inside windows - and with what and if it makes a difference? Sparkling clean? (Anti fog don't work for me.) Scuba dive equipment (like in a jacuzzi), washing up liquid, fabric softener, use other car etc etc

Mo

Never ever cleaned the inside of the glass on the Fabia and I've only used glass cleaner on the inside of the windows of the Mondeo whenever I remember (so about 3 times since I bought it!) and never had any probs at all!

Chris

See, I hate people who have no misting I'm wondering (serious question) whether you clean your inside windows - and with what and if it makes a difference? Sparkling clean? (Anti fog don't work for me.) Scuba dive equipment (like in a jacuzzi), washing up liquid, fabric softener, use other car etc etc

Mo

I keep my dive mask clear with spit! Don't fancy doing thaf for the windscreen to be honest:P

Phil

i will really really miss the heated windscreen that i have on the mondy when i move to the vrs..... :( saved me many an hour

I keep my dive mask clear with spit! Don't fancy doing thaf for the windscreen to be honest:P

Phil

:holmes: As human beings exude a lot of water and heat (and I tend to sit forward so breathe on the screen Tsk!), does your car mist up less if you drive in your wetsuit?

A solution perhaps? :boing:

Mo

Mine used to mist up all the time, when I was using a mixture of A/C and non A/C (not at the same time ), but since using A/C non stop its been absolutly fine. Uses a bit more fuel, but it all adds to global warming - so thats ok by me

Ok, figured something out. Car started steaming up again on the way home (no A/C usage this time) and so I thought after a blast of the fans only made it worse that I'd try turning 'on' recirculation. And, hey presto, the windows cleared in about a minute. This seems funny as these problems have all been there since Skoda replaced the heater flap motor.

So, is the recirculation set the wrong way round meaning it's on when the light is off etc, or is the fresh air being drawn in and moistened somehow?

When the car is in recirculation mode, you put it in reverse and the tone does not change meaning the car thinks it's already 'on'. Turn recirculation mode off and put it in reverse again and the tone DOES change.

So, how do I actually tell whether it's sucking in fresh air or not? It may be steaming up cos it's just using the same air when it shouldn't be and vice versa.

Ok, figured something out. Car started steaming up again on the way home (no A/C usage this time) and so I thought after a blast of the fans only made it worse that I'd try turning 'on' recirculation. And, hey presto, the windows cleared in about a minute. This seems funny as these problems have all been there since Skoda replaced the heater flap motor.

So, is the recirculation set the wrong way round meaning it's on when the light is off etc, or is the fresh air being drawn in and moistened somehow?

When the car is in recirculation mode, you put it in reverse and the tone does not change meaning the car thinks it's already 'on'. Turn recirculation mode off and put it in reverse again and the tone DOES change.

So, how do I actually tell whether it's sucking in fresh air or not? It may be steaming up cos it's just using the same air when it shouldn't be and vice versa.

Hmm - seems like the wrong way round! Get the dealer to check if its under warranty.

It is indeed under warranty. Funny thing is the car had it's heat flap changed on Wed along with the rear doors sealed. After just looking in the manual it says not to use the recirculation mode for long as the windows will mist up (self explanatory really). I wonder if it's a programming thing?

Perhaps it thinks it's on recirc mode when it's not and vice versa? Would also explain the behaviour in reverse.

:holmes: As human beings exude a lot of water and heat (and I tend to sit forward so breathe on the screen Tsk!), does your car mist up less if you drive in your wetsuit?

A solution perhaps? :boing:

Mo

Drysuit would be better.........its completely sealed. :eek:

Ok, just tested it with a Jostik and a torch. Put the car on recirculate (the light on) and smoke just flows out from under the passenger footwell, but turn it off (supposedly fresh air) and it immediatly sucks the smoke up under the dash.

This proves it's the wrong way round and it's sucking when it shouldn't be. Ooh err missus!

Ok, just tested it with a Jostik and a torch. Put the car on recirculate (the light on) and smoke just flows out from under the passenger footwell, but turn it off (supposedly fresh air) and it immediatly sucks the smoke up under the dash.

This proves it's the wrong way round and it's sucking when it shouldn't be. Ooh err missus!

Cor blimey! Dunno if you are right or wrong, but do you realise there are probably some hundreds of Briskoda members out in their cars with Jostiks and torches now?

You have a lot to answer for my friend Keep us posted

Mo