Condensation Issue in Headlights

Faults and Technical chat for the Skoda Kodiaq
Old and Grumpy
Posts: 17
Joined: Sat Oct 13, 2018 1:59 pm
Location: Melton Mowbray

Re: Condensation Issue in Headlights

Post by Old and Grumpy » Tue Nov 06, 2018 6:17 pm

Just my thoughts on this topic.

Heat does not cause condensation. Water vapour condenses on contact with a cold surface.

IDEA!

Is there water in the lamp unit which is heated into vapour by the heat of the lamp, and then condenses on the cold lens?

If that is the case then maybe a drain hole is blocked and does not allow the water to drain away.
David, a proud Tyke wasting his time trying to educate southerners.
Kodiaq 1.4TSI SE 2WD, Petrol blue, no extra toys. Melton Mowbray.


bother
Posts: 106
Joined: Mon Sep 11, 2017 8:48 am

Re: Condensation Issue in Headlights

Post by bother » Tue Nov 06, 2018 8:39 pm

Hugh Fanism wrote:
Mon Nov 05, 2018 3:59 pm

Are you saying it's not possible for the humidity to be increasing inside his headlamps when his lights come on? It clearly is increasing or there wouldn't be condensation. If the condensation only occurs when the lights are on it can only be the heat from the lights causing that humidity.
Nope. I said heating air up doesn't cause condensation.

I don't know what's causing the condensation to form but it's either an increase in humidity or a decrease in air temperature.

I think we agree though that it's normal behaviour and the lights are designed to try and ensure it clears asap

In answer to one of the following posts, I suspect there's no benefit, but it's difficult not to have it form. I had several Audi's in the past and they all had condensation inside the light cluster on occasion.
Edition 1.4DSG, Front Sensors, Spacesaver


Hugh Fanism
Posts: 421
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Location: Maidenhead

Re: Condensation Issue in Headlights

Post by Hugh Fanism » Tue Nov 06, 2018 9:13 pm

bother wrote:
Tue Nov 06, 2018 8:39 pm
Hugh Fanism wrote:
Mon Nov 05, 2018 3:59 pm

Are you saying it's not possible for the humidity to be increasing inside his headlamps when his lights come on? It clearly is increasing or there wouldn't be condensation. If the condensation only occurs when the lights are on it can only be the heat from the lights causing that humidity.
Nope. I said heating air up doesn't cause condensation.

I don't know what's causing the condensation to form but it's either an increase in humidity or a decrease in air temperature.

I think we agree though that it's normal behaviour and the lights are designed to try and ensure it clears asap

In answer to one of the following posts, I suspect there's no benefit, but it's difficult not to have it form. I had several Audi's in the past and they all had condensation inside the light cluster on occasion.
You can't have humidity without heat.
1.4 DSG SE L, council blue, acc.
"Johnny ain't so crazy, he's always got a line for the ladies"


bother
Posts: 106
Joined: Mon Sep 11, 2017 8:48 am

Re: Condensation Issue in Headlights

Post by bother » Tue Nov 06, 2018 9:17 pm

Hugh Fanism wrote:
Tue Nov 06, 2018 9:13 pm
You can't have humidity without heat.
🤦‍♂️
Edition 1.4DSG, Front Sensors, Spacesaver


akop.4040
Posts: 13
Joined: Mon Nov 05, 2018 12:00 pm

Re: Condensation Issue in Headlights

Post by akop.4040 » Fri Nov 09, 2018 12:04 pm

Hugh Fanism wrote:
Tue Nov 06, 2018 3:54 pm
akop.4040 wrote:
Tue Nov 06, 2018 11:33 am
Hugh Fanism wrote:
Tue Nov 06, 2018 8:09 am


Are you saying it's not possible for the humidity to be increasing inside his headlamps when his lights come on? It clearly is increasing or there wouldn't be condensation. If the condensation only occurs when the lights are on it can only be the heat from the lights causing that humidity.

I would also expect it to evaporate but there's clearly something else going on here too. I'll be honest, I don't care much for the physics involved.

The facts are:

Conditions are as such to create condensation in the headlight unit.

The headlight unit is designed to have condensation.

I'm sorry, but I'm with the dealer here. When something does something that it's designed to do it isn't faulty.
@Hugh Fanism
This sounds very normal.

The inside of your headlight is heating up when you turn them on, therefore creating
Hey thanks for replying. Few questions-

1. The manual page, it says that any mist formed will go away when the headlights are turned on but in our case it forms after the headlights are turned on and that too in any weather condition rather each night after they are switched on irrespective of the weather. Why is it happening exactly the opposite here?

2. Why is this issue happening with my car only? The other Superb's sold by the same dealer doesn't have this issue. His demo car also is condensation free.

3. As per your fact, why is the headlight unit designed to have condensation? What's the benefit of having condensation?

4. Other VW cars like Audi etc. have the same Xenon headlights. No condensation is formed in them. Why do you think that is?

The condensation is completely gone by the next morning

Once I was driving at night after it stopped raining. There was some water on the road and by the time I reached home the headlights looked like this

Image

Image
I can only answer 3 and 4. I think they're designed with vents and are expected to condensate, with the vents giving way fir the vapour to escape. Cars previously with sealed headlights were able to fill and retain water when the seals are faulty. I think the design is to negate the latter.
And other VW group headlights do condensate.
I get your point that they are designed that way so why aren't all the other Superb's and Kodiaq's having misted headlights here? I am talking about my city because out of all the other same cars that I have seen they are totally mist free.
About the bold part yes they do but some.

Since as per you this mist occurs due to temperature difference minus the water or moist air but in long term can this mist have any drastic impact on the headlight besides blocking the view if we use low beam?


akop.4040
Posts: 13
Joined: Mon Nov 05, 2018 12:00 pm

Re: Condensation Issue in Headlights

Post by akop.4040 » Fri Nov 09, 2018 12:09 pm

Old and Grumpy wrote:
Tue Nov 06, 2018 6:17 pm
Just my thoughts on this topic.

Heat does not cause condensation. Water vapour condenses on contact with a cold surface.

IDEA!

Is there water in the lamp unit which is heated into vapour by the heat of the lamp, and then condenses on the cold lens?

If that is the case then maybe a drain hole is blocked and does not allow the water to drain away.
As per @Hugh Fanism and the Skoda guy, the temperature difference/heat is causing the condensation.

The headlights have been replaced twice once from a demo car and the second time 2 year old headlights were installed. They started misting up minutes after the installation. There is no water inside the windshield cleaner box. About the any crack/damage, there is none as per the dealer. Any other help?

About this line of yours, If that is the case then maybe a drain hole is blocked and does not allow the water to drain away
Water to drain away from where exactly?


akop.4040
Posts: 13
Joined: Mon Nov 05, 2018 12:00 pm

Re: Condensation Issue in Headlights

Post by akop.4040 » Fri Nov 09, 2018 12:14 pm

bother wrote:
Tue Nov 06, 2018 8:39 pm
Hugh Fanism wrote:
Mon Nov 05, 2018 3:59 pm

Are you saying it's not possible for the humidity to be increasing inside his headlamps when his lights come on? It clearly is increasing or there wouldn't be condensation. If the condensation only occurs when the lights are on it can only be the heat from the lights causing that humidity.
Nope. I said heating air up doesn't cause condensation.

I don't know what's causing the condensation to form but it's either an increase in humidity or a decrease in air temperature.

I think we agree though that it's normal behaviour and the lights are designed to try and ensure it clears asap

In answer to one of the following posts, I suspect there's no benefit, but it's difficult not to have it form. I had several Audi's in the past and they all had condensation inside the light cluster on occasion.
As per @Hugh Fanism and the Skoda guy, the temperature difference/heat can and is causing the condensation here.

In my case it clears after we park the car at night and by the morning it is totally cleared. Within how much time I can't say. Is this normal then?

This is exactly what I am trying to understand, in the parking lot there are like ton's of Audi's but none of them has this condensation. So, why is this condensation happening only to a selected few units?

In long term can this condensation have any drastic effect on the headlight besides blocking the view if we use low beam?


Old and Grumpy
Posts: 17
Joined: Sat Oct 13, 2018 1:59 pm
Location: Melton Mowbray

Re: Condensation Issue in Headlights

Post by Old and Grumpy » Fri Nov 09, 2018 1:04 pm

You cannot have condensation without water being present. When warm water vapour meets a cold surface it condenses. There must be water in some form inside the headlight unit. The heat from the headlight forms water vapour, which then condenses on the cold headlight lens. If there is water inside the headlight unit it needs to drain away, so is a drain hole blocked?
David, a proud Tyke wasting his time trying to educate southerners.
Kodiaq 1.4TSI SE 2WD, Petrol blue, no extra toys. Melton Mowbray.


akop.4040
Posts: 13
Joined: Mon Nov 05, 2018 12:00 pm

Re: Condensation Issue in Headlights

Post by akop.4040 » Sat Nov 10, 2018 11:11 am

Old and Grumpy wrote:
Fri Nov 09, 2018 1:04 pm
You cannot have condensation without water being present. When warm water vapour meets a cold surface it condenses. There must be water in some form inside the headlight unit. The heat from the headlight forms water vapour, which then condenses on the cold headlight lens. If there is water inside the headlight unit it needs to drain away, so is a drain hole blocked?
About the bold part, trust me I had a discussion for more than 20 minutes on this subject but the concerned person here didn't agree to it and said that the temperature difference is causing this and since he's an engineer he knows better.

The headlights have been changed, swapped from demo car or old headlight is another concern, so something else like the drain hole that you have mentioned is letting the water in. Can you please tell me where is this drain hole located, if possible with a photo? I will have to look myself as the dealer isn't doing anything.

I really don't understand 1 thing, the windshield washer is empty. I haven't water washed the car in about the past 5-6 months so from where the hell is the water coming from? Fine it might be inside say from wherever but wouldn't the same be evaporated by now? The dealership did not check the stuff fully for any moisture present, they only checked it for leakage or breakage and I am sure about it because if there was any then they would have charged me which is the only thing they are good at.


Old and Grumpy
Posts: 17
Joined: Sat Oct 13, 2018 1:59 pm
Location: Melton Mowbray

Re: Condensation Issue in Headlights

Post by Old and Grumpy » Sat Nov 10, 2018 12:23 pm

Hi Akop.4040

I can't answer your questions about where the water is coming from or where any holes might be.

I am using my "O" level GCE Physics knowledge from 1963 to state the basic facts.

1. You cannot have condensation without water vapour being present.

2. Water vapour condenses when it comes into contact with a colder surface.

3. Heat does not cause condensation. Heat causes humidity by heating water into water vapour.

Sorry, those are basic facts and anyone who disagrees needs to go back to school.
David, a proud Tyke wasting his time trying to educate southerners.
Kodiaq 1.4TSI SE 2WD, Petrol blue, no extra toys. Melton Mowbray.


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