Fabia 2 screen misting up

[phs12]

I bought my Fabia 2 in Sept 2023. It’s the first car I’ve had with Air Con (Manual).

 

Symptoms;

 

1. If I have the air con on speed 1 from the start of a journey the screen stays clear. If I then go to a supermarket or visit my elderly mother, when I get back to the car there is a light misting on the screen. When I operate the air con (engine on) the misting initially gets worse then slowly clears.
2. Last Thursday, I didn’t use the air con, went shopping, came back to the car and the screen was clear. Then I randomly thought, what happens if I turn the Air Distribution dial to feet, turn the Control dial to hot and turn the Blower switch to 3 with the Air Con off; the screen started misting up so badly I had to stop and open the front windows and turned Air Distribution dial to screen, which cleared the misting.

 

Other factors (relating to what I’ve read on here);

 

1. There is no water in the spare wheel well.
2. I regularly open all the doors to allow water to drain away (thanks Skoda!).
3. I can’t feel any wet carpets either on the front passenger side or the driver’s side.
4. The cabin filter is not wet.

 

Last Thursday, I was about to attempt to remove the wiper arms and plastic scuttle cover, when I decided to first try the suggestion on here from an Octavia owner to remove a wheel arch liner to check that water drains through. I did this and water drained into the container I placed under the car (also drained through a hole in a plastic protector attached to the floorpan). So I guess the drains are clear?

 

 

This morning I went to check that condensate drain was clear, expecting to see a flap as shown in Breezy Pete’s post on this thread

 

https://www.briskoda.net/forums/topic/520270-mistingfogging-windows/

 

but I only have what Ethanthecarknownothing shows in his photo, just a pipe sticking out (with a single dead spider over it), so no flap to check (I have two photos if needed) and Breezy Pete suggests I would have to wait for a warm day to see water coming out of that pipe.

 

So, what can I do next please?

 

 

 

 

 

[xman]

Whenever you use aircon, humidity in the air that passes through the evaporator (the cooling element in the heating/ventilation) condenses and the condensate water should drain out though the bottom mounted condensate drain tube. How much water depends on the humidity in the air (outside or inside if on recirc setting)

 

Not all water manages to drain for a variety of reasons, perhaps partly blocked drain or a build up of debris or fungis/bacteria or just hanging on the evaporator fins. So when you restart the car after previously using ac, its normal for humid air to come out of the vents and mist up the screen initially. Turning on the ac will dry the air (water going elsewhere) and clear the screen. Alternatively turn the blower up to dry the evaporator out, how long it takes depends on the amount of water still in the evaporator.

 

A good habit is to turn a/c off a few minutes before you complete your drive but leave the blower on to dry out the evaporater before you turn off the engine. This will stop bacteria, fungus and bad smells developing due to stagnant water in the evaporator when the car is stood. It also stops the initial misting you get when starting.

 

 

[Paws4Thot]

@phs12 When was the cabin pollen filter last replaced?

[xman]

3 minutes ago, Paws4Thot said:

@phs12 When was the cabin pollen filter last replaced?

 

I doubt that the state of the filter (which the op states is not wet) has much bearing on the misting, which as described sounds fairly normal bearing in mind how the a/c is being used then not but just the blower.

 

If you can get under the car, take a long qtip or similar implement and poke up  the a/c drain pipe to clear any blockage which may have built up due to lack of regular filter changes. I suppose back flushing water may help in bad cases.

 

But a clean filter is always helpful with maintaining decent airflow and preventing bacteria/fungus entering the evaporator and so the dreaded smelly a/c.

 

How quickly the a/c clears the screen depends on how much refrigerant is left in the system. So a re-gas may help if the a/c is weak.

 

Turning off a/c 3 or 4 mins before the end of a journey but keeping the blower going helps stop the misting and a/c going smelly.

 

 

 

 

[phs12]

27 minutes ago, Paws4Thot said:

@phs12 When was the cabin pollen filter last replaced?

oops! Looks like 2018 is the last charge for one on the invoices that were passed on to me and ref'd in the service book. I get the impression a lot of garages don't bother as it's often not part of the service schedule.

 

Might also get one of these air con cleansers that you use inside the car.

[phs12]

6 hours ago, phs12 said:

Last Thursday, I didn’t use the air con, went shopping, came back to the car and the screen was clear. Then I randomly thought, what happens if I turn the Air Distribution dial to feet, turn the Control dial to hot and turn the Blower switch to 3 with the Air Con off; the screen started misting up so badly I had to stop and open the front windows and turned Air Distribution dial to screen, which cleared the misting.

 

Thanks for your reply @xman. So, maybe there's nothing wrong with the air con? What about the above when the air con was off?

[xman]

Reread my posts. Water builds up in the evaporator compartment when a/c is used due to condensation on the evaporator (below dew point temperature) If you turn off the engine without turning of the a/c previously you're relying on that water draining while stood. Sometimes in hot humid weater you can see a pool of water on the ground from that drain. But often the evaporator which might even have iced up will still be wet and any mould formed (bateria/fungus) will also be sodden, the drainage may not be clear. So if you restart the car without a/c, air blowing through will pick up high humidity as the compartment  dries out.

 

Sounds as if you could do with a filter change and check the drainage is not blocked.

 

Of course if your screen mists up the 1st thing you should do is turn the direction control to the screen, turn the blower up and if you want to clear quickly then turn on the a/c.

 

 

[Breezy_Pete]

9 hours ago, phs12 said:

 

 What about the above when the air con was off?

Any chance you had rain/puddle water dripping off shoe soles onto mats on that occasion?

 

Blasting air at the floor would have started to evaporate that fast. No airflow on cold glass would have given that somewhere good to condense again straight away.

 

 

[phs12]

Hi Pete,

 

No, there was no rain that day. 

 

Maybe the lesson is to heat the screen before sending any heat to the feet. Also, maybe the cooling system water wasn't warm enough to be sending heat to the feet, as I'd only just started off from the supermarket and had only driven a short distance from mum's house before that. Although why would that mist the screen up?

[phs12]

13 hours ago, xman said:

If you can get under the car, take a long qtip or similar implement and poke up  the a/c drain pipe to clear any blockage which may have built up due to lack of regular filter changes.

Thanks for your posts @xman

 

Is this the a/c drain pipe?

 

Edited 4 March by phs12

[Breezy_Pete]

Yes. Looks like the flap of sound insulation that originally covered it to prevent dirt/critter ingress has been torn right off.

[phs12]

1 hour ago, Breezy_Pete said:

Yes. Looks like the flap of sound insulation that originally covered it to prevent dirt/critter ingress has been torn right off.

Thanks @Breezy_Pete

 

No, it was just folded up. Here's another photo I took same day (it's horizontal though, so not easy to see);

 

Edited 4 March by phs12

[Breezy_Pete]

Very few people have ever looked under that flap, so hardly anyone knows about the drain being there.